Answers - Weebly...Answers A27 2. x = 18; Lines s and t are parallel when the marked consecutive...

14
Answers Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A22 127. ( )( ) 2 7 x x + 128. ( )( ) 12 11 x x + 129. ( )( ) 7 4 x x + 130. ( )( ) 5 3 x x 131. ( )( ) 2 3 x x 132. ( )( ) 4 9 x x + 133. ( )( ) 1 1 x x + 134. ( )( ) 3 3 x x + 135. ( )( ) 5 5 x x + 136. ( )( ) 2 3 4 x x + 137. ( )( ) 3 5 7 x x 138. ( )( ) 5 2 4 x x + + 139. 8 and 3 x x = − = − 140. 6 and 2 x x = − = 141. 12 and 1 x x = − = 142. 9 and 8 x x = − = − 143. 5 and 4 x x = − = 144. 10 and 7 x x = − = − 145. 3 and 1 x x = − = 146. 5 and 2 x x = − = 147. 11 and 1 x x = − = 148. 3 2 and 5 x x = − = 149. 4 5 and 3 x x = − = 150. 7 1 3 2 and x x = − = 151. a. 7 words per min b. 87.5 words c. 105 words d. 17.5 words Chapter 3 3.1 Start Thinking right triangle; no; no; Because points B and C connect perpendicular lines, you cannot plot either point to make a perpendicular segment or a parallel segment. 3.1 Warm Up 1. Sample answer: BC 2. GE 3. CG 4. , , AB BC BD 5. Sample answer: and FE FG 6. Sample answer: D 3.1 Cumulative Review Warm Up 1. ( ) 4, 11 K 2. ( ) 27, 18 J 3. ( ) 21, 2 K 3.1 Practice A 1. and AB CD 2. and AC CD 3. no; AB CD and by the Parallel Postulate (Post. 3.1), there is exactly one line parallel to AB through point C. 4. no; They are intersecting lines. 5. 2 and 8, 3 and 5 6. 1 and 7, 4 and 6 7. 1 and 5, 2 and 6, 3 and 7, 4 and 8 8. 2 and 5, 3 and 8 9. no; By definition, skew lines are not coplaner. 10. 2 pairs; 4 pairs; ( ) 2 2 n pairs 11. a. AB and , CD AC and BD b. AC and , CD BD and CD c. 2 and 5, 3 and 8 C A B

Transcript of Answers - Weebly...Answers A27 2. x = 18; Lines s and t are parallel when the marked consecutive...

Answers

Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A22

127. ( )( )2 7x x+ − 128. ( )( )12 11x x− +

129. ( )( )7 4x x− + 130. ( )( )5 3x x− −

131. ( )( )2 3x x− − 132. ( )( )4 9x x+ −

133. ( )( )1 1x x+ − 134. ( )( )3 3x x+ −

135. ( )( )5 5x x+ − 136. ( )( )2 3 4x x− +

137. ( )( )3 5 7x x− − 138. ( )( )5 2 4x x+ +

139. 8 and 3x x= − = −

140. 6 and 2x x= − =

141. 12 and 1x x= − =

142. 9 and 8x x= − = −

143. 5 and 4x x= − =

144. 10 and 7x x= − = −

145. 3 and 1x x= − =

146. 5 and 2x x= − =

147. 11 and 1x x= − =

148. 32 and 5x x= − =

149. 45 and 3x x= − =

150. 713 2 and x x= − =

151. a. 7 words per min b. 87.5 words c. 105 words d. 17.5 words

Chapter 3 3.1 Start Thinking

right triangle; no; no; Because points B and C connect perpendicular lines, you cannot plot either point to make a perpendicular segment or a parallel segment.

3.1 Warm Up

1. Sample answer: BC

2. GE

3. CG

4. , ,AB BC BD

5. Sample answer: andFE FG

6. Sample answer: D

3.1 Cumulative Review Warm Up 1. ( )4, 11K 2. ( )27, 18J − − 3. ( )21, 2K −

3.1 Practice A

1. andAB CD

2. andAC CD

3. no; AB CD

and by the Parallel Postulate (Post. 3.1), there is exactly one line parallel to AB

through

point C.

4. no; They are intersecting lines.

5. 2∠ and 8,∠ 3∠ and 5∠

6. 1∠ and 7,∠ 4∠ and 6∠

7. 1∠ and 5,∠ 2∠ and 6,∠ 3∠ and 7,∠ 4∠ and 8∠

8. 2∠ and 5,∠ 3∠ and 8∠

9. no; By definition, skew lines are not coplaner.

10. 2 pairs; 4 pairs; ( )2 2n − pairs

11. a. AB

and ,CD

AC

and BD

b. AC

and ,CD

BD

and CD

c. 2∠ and 5,∠ 3∠ and 8∠

CA

B

Answers

Copyright © Big Ideas Learning, LLC Geometry All rights reserved. Answers

A23

d. 1∠ and 5,∠ 2∠ and 6,∠ 3∠ and 7,∠ 4∠ and 8∠

e. 2∠ and 8,∠ 3∠ and 5∠ f. 1∠ and 7,∠ 4∠ and 6∠

3.1 Practice B 1. lines c and d 2. lines e and f

3. Sample answer: lines c and e

4. planes A and B

5. no; lines f and g appear to be coplanar and although they do not intersect, there is not enough information to determine that the lines are parallel.

6. no; lines e and g appear to be coplanar and intersect at a 90° angle, but there is not enough information to determine that the lines are perpendicular.

7. alternate interior 8. corresponding

9. alternate exterior 10. corresponding

11. consecutive exterior

12. no; The lines do not intersect, however they could be coplanar to a third plane.

13. a. true; The road and the sidewalk appear to lie in the same plane and they do not intersect. b. false; The road and the crosswalk appear to

intersect. c. true; A properly installed stop sign intersects the

ground at a 90° angle.

3.1 Enrichment and Extension 1. yes; The two lines of intersection are coplanar

because they are both in the third plane. The two lines do not intersect because they are in parallel planes. Because they are coplanar and do not intersect, they are parallel.

2.

Line a appears to be parallel to line c; If two lines are parallel to the same line, then they are parallel to each other.

3.

Line seems to be parallel to line n; If two lines are perpendicular to the same line, then they are parallel to each other.

4.

5.

6. a. 5, 11, 17∠ ∠ ∠

b. 5, 9, 17∠ ∠ ∠

c. 8, 12, 17∠ ∠ ∠

d. 7, 9, 18∠ ∠ ∠

e. 2, 10, 14∠ ∠ ∠

f. 4, 10, 16∠ ∠ ∠ g. 3, 11, 15∠ ∠ ∠

h. 15∠

3.1 Puzzle Time A YARDSTICK

m

n

m

n

P

B

A

a

b

c

Answers

Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A24

3.2 Start Thinking

one angle measure; With the measurement of one of the angles, you can use the properties of corresponding angles, alternative interior angles, alternate exterior angles, and consecutive interior angles to find the other seven measurements.

3.2 Warm Up 1. 34° 2. 17° 3. 147°

4. 53° 5. 86° 6. 84°

3.2 Cumulative Review Warm Up 1.

2.

3.

4.

3.2 Practice A 1. 1 87 , 2 93 ; 1 87m m m∠ = ° ∠ = ° ∠ = ° by the

Alternate Interior Angles Theorem (Thm. 3.2). 2 93m∠ = ° by the Consecutive Interior Angles

Theorem (Thm. 3.4).

2. 1 78 , 2 78 ; 1 78m m m∠ = ° ∠ = ° ∠ = ° by the Corresponding Angles Theorem (Thm. 3.1).

2 78m∠ = ° by the Alternate Exterior Angles Theorem (Thm. 3.3).

3. ( )8; 37 6 1148 68

x

xx

° = − °

==

4. 10;

( )2 142 180

2 9 142 180

2 18 142 1802 160 180

2 2010

m

x

xx

xx

∠ + ° = °

+ ° + ° = °

+ + =+ =

==

5. 1 112 , 2 68 , 3 112 ;m m m∠ = ° ∠ = ° ∠ = ° Because the 112° angle is a vertical angle to 1,∠ by the Vertical Angles Congruence Theorem (Thm. 2.6) they are congruent. Because 1∠ and 2∠ are consecutive interior angles, they are supplementary by the Consecutive Interior Angles Theorem (Thm. 3.4). Because the given 112° angle and 3∠are alternate exterior angles, they are congruent by the Alternate Exterior Angles Theorem (Thm. 3.3).

6. 1 45 , 2 45 , 3 135 ;m m m∠ = ° ∠ = ° ∠ = ° Because the given 45° angle is a corresponding angle with

1,∠ and 1∠ is a corresponding angle with 2∠ , they are all congruent by the Corresponding Angles Theorem (Thm. 3.1). Because the 45° angle is a consecutive interior angle with 3,∠ they are supplementary by the Consecutive Angles Theorem (Thm. 3.4).

1 2

3 4

m

t

5 6

7 8

45°

R

R

A

B

CD

R

A B

C

D

R S

x y

Answers

Copyright © Big Ideas Learning, LLC Geometry All rights reserved. Answers

A25

7.

8.

1 90 ;m∠ = ° Because 1∠ is congruent and supplementary to 2,∠ the measure of each angle is 90°.

3.2 Practice B 1. 1 41 , 2 41 ; 1 41m m m∠ = ° ∠ = ° ∠ = ° by the

Corresponding Angles Theorem (Thm. 3.1). 2 41m∠ = ° by the Vertical Angles Congruence

Theorem (Thm. 2.6).

2. 1 124 , 2 124 ; 1 124m m m∠ = ° ∠ = ° ∠ = ° by the Alternate Exterior Angles Theorem (Thm. 3.3).

2 124m∠ = ° by the Vertical Angles Congruence Theorem (Thm. 2.6).

3. 16; ( ) ( )24 3 832 332 216

x x

x xx

x

+ ° = − °

+ ===

4. 51; ( ) ( )2 27 3 25 1803

2 18 3 25 1803

11 7 1803

51

x x

x x

x

x

+ ° + − ° = °

+ + − =

− =

=

5. 1 102 , 2 102 , 3 78 ;m m m∠ = ° ∠ = ° ∠ = ° Because the given 102° angle is an alternate interior angle with 1,∠ they are congruent by the Alternate Interior Angles Congruence Theorem (Thm. 3.2). Because the given 102° angle and 2∠ are alternate exterior angles, they are congruent by the Alternate Exterior Angles Theorem (Thm. 3.3). Because 2∠and 3∠ are a linear pair, they are supplementary by the Linear Pair Postulate (Post. 2.8).

6. 1 68 , 2 68 , 3 112 ;m m m∠ = ° ∠ = ° ∠ = ° Because the given 68° angle and 1∠ are corresponding angles, they are congruent by the Corresponding Angles Theorem (Thm. 3.1). Because 1∠ and 2∠ are alternate exterior angles, they are congruent by the Alternate Exterior Angles Theorem (Thm. 3.3). Because angle 2∠ and 3∠ are consecutive angles, they are supplementary by the Consecutive Interior Angles Theorem (Thm. 3.4).

7. 1 110 , 2 70 ;m m∠ = ° ∠ = ° Because ( ) ( )3 5 4 30 ,x x+ ° = − ° the value of x is 35. So, ( )3 5 110x + ° = ° and ( )4 30 110 .x − ° = ° By the Corresponding Angles Theorem (Thm. 3.1),

1 110 .m∠ = ° By the Linear Pair Postulate (Post 2.8), 2 70 .m∠ = °

STATEMENTS REASONS

1. p q 1. Given

2. 1 2 180m m∠ + ∠ = ° 2. Linear Pair Postulate (Post. 2.8)

3. 2 3 180m m∠ + ∠ = ° 3. Consecutive Interior Angles Theorem (Thm. 3.4)

4. 1 3∠ ≅ ∠ 4. Congruent Supplements Theorem (Thm. 2.4)

STATEMENTS REASONS

1. 1 2∠ ≅ ∠ 1. Given

2. 1 3∠ ≅ ∠ 2. Vertical Angles Congruence Theorem (Thm. 2.6)

3. 2 3∠ ≅ ∠ 3. Transitive Property of Angle Congruence (Thm. 2.2)

12 p

q

t

3

Answers

Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A26

8. 3, 5, 6, 7, 9,∠ ∠ ∠ ∠ ∠ and 10;∠ Because 1∠ and 3∠ are supplementary to 2∠ by the Consecutive

Interior Angles Theorem (Thm. 3.4), 1 3∠ ≅ ∠ by the Congruent Supplements Theorem (Thm. 2.4).

1 5∠ ≅ ∠ and 1 7∠ ≅ ∠ by the Alternate Interior Angles Theorem (Thm. 3.3). 1 6∠ ≅ ∠ by the Vertical Angles Congruence Theorem (Thm. 2.6). Because 3 9∠ ≅ ∠ by the Vertical Angles Congruence Theorem (Thm. 2.6), 1 9∠ ≅ ∠ by the Transitive Property of Angle Congruence (Thm. 2.2). Because 5 10∠ ≅ ∠ by the Vertical Angles Congruence Theorem (Thm. 2.6),

1 10∠ ≅ ∠ by the Transitive Property of Angle Congruence (Thm. 2.2).

3.2 Enrichment and Extension 1. 65, 60x y= = 2. 13, 12x y= =

3.

4. 1 35 ,m∠ = ° 2 145 ,m∠ = ° 3 111 ,m∠ = °4 69 ,m∠ = ° 5 111 ,m∠ = ° 6 69 ,m∠ = °7 145 ,m∠ = ° 8 35 ,m∠ = ° 9 69 ,m∠ = °10 111 ,m∠ = ° 11 69 ,m∠ = ° 12 111 ,m∠ = °13 76 ,m∠ = ° 14 104 ,m∠ = ° 15 76 ,m∠ = °16 104 ,m∠ = ° 17 104 ,m∠ = ° 18 76 ,m∠ = °19 104 ,m∠ = ° 20 76m∠ = °

5. 1 100 ,m∠ = ° 2 80 ,m∠ = ° 3 80 ,m∠ = °4 100 ,m∠ = ° 5 100 ,m∠ = ° 6 56 ,m∠ = °7 24 ,m∠ = ° 8 24 ,m∠ = ° 9 56 ,m∠ = °10 100 ,m∠ = ° 11 156 ,m∠ = ° 12 24 ,m∠ = °13 24 ,m∠ = ° 14 156 ,m∠ = ° 15 124 ,m∠ = °16 56 ,m∠ = ° 17 124 ,m∠ = ° 18 56 ,m∠ = °19 100 ,m∠ = ° 20 80 ,m∠ = ° 21 100 ,m∠ = °22 80 ,m∠ = ° 23 156 ,m∠ = ° 24 24 ,m∠ = °25 24 ,m∠ = ° 26 156 ,m∠ = ° 27 100 ,m∠ = °28 56 ,m∠ = ° 29 24 ,m∠ = ° 30 24 ,m∠ = °31 56 ,m∠ = ° 32 100m∠ = °

3.2 Puzzle Time GEOMETRY

3.3 Start Thinking

120°; 60° and 120°, respectively; The angles are the same as the shopping mall sidewalks because they are parallel to them.

3.3 Warm Up 1. 10, 12x y= = 2. 5, 3x y= =

3.3 Cumulative Review Warm Up 1. 2 1m m∠ = ∠ 2. GH HJ+ 3. 4 GH•

3.3 Practice A 1. 44;x = Lines s and t are parallel when the marked alternate exterior angles are congruent.

( ) ( )3 8 2 103 24 2 20

44

x x

x xx

− ° = + °

− = +=

A D

B C

STATEMENTS REASONS

1. ,AB DC AD BC 1. Given

2. A∠ and B∠ are supplementary.

2. Consecutive Interior Angles Theorem (Thm. 3.4)

3. B∠ and C∠ are supplementary.

3. Consecutive Interior Angles Theorem (Thm. 3.4)

4. 180m A m B∠ + ∠ = ° 4. Definition of supplementary angles

5. 180m B m C∠ + ∠ = ° 5. Definition of supplementary angles

6. m B m C∠ + ∠

6. Substitution

7. m A m C∠ = ∠ 7. Subtraction Property of Equality

8. A C∠ ≅ ∠ 8. Definition of congruent angles

m A m B∠ + ∠ =

60°

walkways

ShoppingMall

streets

60°

Answers

Copyright © Big Ideas Learning, LLC Geometry All rights reserved. Answers

A27

2. 18;x = Lines s and t are parallel when the marked consecutive interior angles are supplementary. ( )4 12 120 180

4 108 1804 72

18

x

xxx

− ° + ° = °

+ ===

3. yes; Corresponding Angles Converse (Thm. 3.5)

4. no

5. This diagram shows that the vertical angles are congruent, and we do not have enough information to prove that .m n

6.

7. no; The labeled angles must be congruent to prove the wings are parallel.

3.3 Practice B 1. 12;x = Lines s and t are parallel when the marked alternate exterior angles are congruent.

( ) ( )4 16 7 2036 312

x x

xx

+ ° = − °

==

2. 26;x = Lines s and t are parallel when the marked consecutive interior angles are supplementary. ( ) ( )2 15 3 20 180

2 30 3 20 1805 50 180

5 13026

x x

x xx

xx

+ ° + + ° = °

+ + + =+ =

==

3. yes; Alternate Exterior Angles Converse (Thm. 3.7)

4. yes; Consecutive Interior Angles Converse (Thm. 3.8)

5. a. yes; Lines a and b are parallel by the Alternate Interior Angles Converse (Thm. 3.6). Lines b and c are parallel by the Alternate Exterior Angles Converse Theorem (Thm. 3.7). Line c and d are parallel by the Corresponding Angles Converse (Thm. 3.5). Lines b and c are parallel by the Alternate Exterior Angles Converse (Thm. 3.7). By the Transitive Property of Parallel Lines (Thm. 3.9), all the lines of latitude are parallel. b. no; There is not enough information to prove that

the lines of longitude are parallel.

6. a. 27, 13, 9;x y z= = = Lines p and q are parallel when the marked alternate exterior angles are congruent.

( ) ( )3 1 4 303 3 4 30

27

x x

x xx

− ° = − °

− = −=

Lines q and r are parallel when the marked corresponding angles are congruent.

( ) ( )( )4 30 6

4 27 30 6

78 613

x y

y

yy

− ° = °

− =

==

The angles 6 y° and ( )6 8z + ° form a linear pair, so they are supplementary.

( )( ) ( )

6 6 8 180

6 13 6 8 180

78 6 48 1806 54

9

y z

z

zzz

° + + ° = °

+ + =

+ + ===

b. yes; Because ( )3 1 78 and 6 78 ,x y− ° = ° ° = °lines p and q are parallel by the Alternate Exterior Converse (Thm. 3.7).

STATEMENTS REASONS

1. 1 and 2∠ ∠ are supplementary.

1. Given

2. 2 and 3∠ ∠ are supplementary.

2. Linear Pair Postulate (Post 2.8)

3. 1 3∠ ≅ ∠ 3. Congruent Supplements Theorem (Thm. 2.4)

4. p q 4. Corresponding Angles Converse (Thm. 3.5)

Answers

Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A28

7.

3.3 Enrichment and Extension 1. 78°

2.

STATEMENTS REASONS

1. 1 2∠ ≅ ∠ 1. Given

2. c d 2. Alternate Exterior Angles Converse (Thm. 3.7)

3. 2 3∠ ≅ ∠ 3. Given

4. a b 4. Alternate Interior Angles Converse (Thm. 3.6)

5. 3 4∠ ≅ ∠ 5. Corresponding Angles Theorem (Thm. 3.1)

6. 1 4∠ ≅ ∠ 6. Transitive Property of Angle Congruence (Thm. 2.2)

STATEMENTS REASONS

1. AC is parallel to .FG BD is the bisector of .CBE∠ DE is the bisector of .BEG∠

1. Given

2. CBE BEF∠ ≅ ∠ 2. Alternate Interior Angles Theorem (Thm. 3.2)

3. m CBEm BEF

∠= ∠

3. Properties of Angle Congruence (Thm. 2.2)

4. ABE BEG∠ ≅ ∠ 4. Alternate Interior Angles Theorem (Thm. 3.2)

5. m ABEm BEG

∠= ∠

5. Properties of Angle Congruence (Thm. 2.2)

6. 180CBE ABE∠ + ∠

= ° 6. Definition of linear

pair

7. 180CBE BEG∠ + ∠

= ° 7. Substitution

8. 12 CBE DBE∠ = ∠ 8. Definition of angle bisector

9. 12 BEG BED∠ = ∠ 9. Definition of angle bisector

10.

( )

1 12 2

12 180

CBE BEG∠ + ∠

= °

10. Multiplication Property of Equality

11. 1 12 290

CBE BEG∠ + ∠

= °

11. Simplify

12. 90

DBE BED∠ + ∠= °

12. Substitution

13. 180

m DBE m BEDm EDB

∠ + ∠+ ∠ = °

13. Property of triangles

14. 180 90 EDB° = ° + ∠ 14. Substitution

15. 90 EDB° = ∠ 15. Subtraction Property of Equality

Answers

Copyright © Big Ideas Learning, LLC Geometry All rights reserved. Answers

A29

3. a. one line b. an infinite number of lines c. one plane

4. a. 137° b. 71° c. 137° d. 43° e. 71°

5.

3.3 Puzzle Time BECAUSE HE WANTED TO SEE TIME FLY

3.4 Start Thinking Sample answer: framing square and chalk line; A framing square ensures cuts made with saws are precise. The chalk line helps builders keep a horizontal surface when needed.

3.4 Warm Up 1. 25 cm 2. 33 cm

3. 478.5 cm2 4. 46 cm 5. 7 cm

3.4 Cumulative Review Warm Up

1. Given AB CD≅ , prove CD AB≅

2. Given A∠ , prove A A∠ ≅ ∠

3.4 Practice A 1. about 5.7 units

2.

3. none; The only thing that can be concluded from the diagram is that n⊥ and .m p⊥ In order to say that the lines are parallel, you need to know something about the intersections of and p or m and .n

STATEMENTS REASONS

1. CA ED

45m FED∠ = ° 1. Given

2. ABE∠ and DEB∠ are supplementary

2. Consecutive Interior Angles Theorem (Thm. 3.4)

3. 180

m ABE m DEB∠ + ∠= °

3. Definition of supplementary angles

4. 45180

m ABE∠ + °= °

4. Substitution Property of Equality

5. 135m ABE∠ = ° 5. Subtraction Property of Equality

6. 135m FBC∠ = ° 6. Vertical Angles Congruence Theorem (Thm. 2.6)

7. 45m GCA∠ = ° 7. Given

8. 135 45 180° + ° = ° 8. Addition

9. 180

m FBC m GCA∠ + ∠= °

9. Substitution Property of Equality

10. andFBC GCA∠ ∠ are supplementary.

10. Definition of supplementary angles.

11. EF CG

11. Consecutive Interior Angles Converse Theorem (Thm. 3.8)

STATEMENTS REASONS

1. AB CD≅ 1. Given

2. AB CD= 2. Definition of congruent segments

3. CD AB= 3. Symmetric Property of Equality

4. CD AB≅ 4. Definition of congruent segments

STATEMENTS REASONS

1. A∠ 1. Given

2. m A m A∠ = ∠ 2. Reflexive Property of Angle Measures

3. A A∠ ≅ ∠ 3. Definition of congruent angles

m

P

×

Answers

Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A30

4. ||b c ; Because a b⊥ and a c⊥ , lines b and c are parallel by the Lines Perpendicular to a Transversal Theorem (Thm. 3.12).

5.

6. no; There is only one perpendicular bisector that can be drawn, but there is an infinite number of perpendicular lines.

7. || , || , ||w x w z x z ; Because w b⊥ and , ||x b w x⊥ by the Lines Perpendicular to a

Transversal Theorem (Thm 3.12). Because w b⊥ and , ||z b w z⊥ by the Lines Perpendicular to a Transversal Theorem (Thm 3.12). Because ||w x and || , ||w z x z by the Transitive Property of Parallel Lines Theorem (Thm. 3.9).

3.4 Practice B

1. 2 5 units

2. ||g h ; Because e g⊥ and e h⊥ , lines g and h are parallel by the Lines Perpendicular to a Transversal Theorem (Thm. 3.12).

3. || , || , ||n m n m ; Because j ⊥ and j n⊥ , lines and n are parallel by the Lines

Perpendicular to a Transversal Theorem (Thm. 3.12). Because k m⊥ and k n⊥ , lines m and n are also parallel by the Lines Perpendicular to a Transversal Theorem (Thm. 3.12). Because || n and ||m n , lines and m are parallel by the Transitive Property of Parallel Lines Theorem (Thm. 3.9).

4. yes; Because || ,e f a e⊥ and c e⊥ , lines a and c are perpendicular to line f by the Perpendicular Transversal Theorem (Thm. 3.11). Because , , ,a f b f c f⊥ ⊥ ⊥ and ,d f⊥ by the Lines Perpendicular to a Transversal Theorem (Thm. 3.12) and the Transitive Property of Parallel Lines (Thm. 3.9), lines a, b, c, and d are all parallel to each other.

5.

6. 1 90 , 2 15 , 3 90 ,m m m∠ = ° ∠ = ° ∠ = ° 4 45 , 5 15 ;m m∠ = ° ∠ = ° 1 90 ,m∠ = ° because

it is vertical angles with a right angle, so it has the same angle measure. 2 90 75 15 ,m∠ = ° − ° = ° because it is complementary to the 75° angle.

3 90 ,m∠ = ° because it is marked as a right angle. 4 75 30 45 ,m∠ = ° − ° = ° because together with

the 30° angle, the angles are vertical angles with the 75° angle, so the angle measures are equal.

5 15 ,m∠ = ° because it is vertical angles with 2,∠so the angles have the same measure.

7. no; You do not know anything about the relationship between lines x and y or x and z.

STATEMENTS REASONS

1. 1 2∠ ≅ ∠ 1. Given

2. e h⊥ 2. Linear Pair Perpendicular Theorem (Thm. 3.10)

3. ||e f 3. Lines Perpendicular to a Transversal Theorem (Thm. 3.12)

4. ||e g 4. Transitive Property of Parallel Lines (Thm. 3.9)

STATEMENTS REASONS

1. 1 2∠ ≅ ∠ 1. Given

2. a c⊥ 2. Linear Pair Perpendicular Theorem (Thm. 3.10)

3. ||c d 3. Given

4. a d⊥ 4. Perpendicular Transversal Theorem (Thm. 3.9)

5. b d⊥ 5. Given

6. ||a b 6. Lines Perpendicular to a Transversal Theorem (Thm. 3.12)

Answers

Copyright © Big Ideas Learning, LLC Geometry All rights reserved. Answers

A31

3.4 Enrichment and Extension

1.

2.

STATEMENTS REASONS

1. ; 3AC BC⊥ ∠ is complementary to 1∠

1. Given

2. 1∠ is complementary to 2∠

2. Definition of perpendicular lines

3. 1 290

m m∠ + ∠= °

3. Definition of complementary angles

4. 1 390

m m∠ + ∠= °

4. Definition of complementary angles

5. 1 21 3

m mm m

∠ + ∠= ∠ + ∠

5. Substitution

6. 2 3m m∠ = ∠ 6. Substitution Property of Equality

7. 3 2m m∠ = ∠ 7. Symmetric Property of Equality

8. 3 2∠ ≅ ∠ 8. Definition of congruent angles

STATEMENTS REASONS

1. AB bisects DAC∠ ; CB bisects ECA∠ 2 45

3 45mm

∠ = °∠ = °

1. Given

2. 2 1m m∠ = ∠ 2. Definition of angle bisector

3. 1 45m∠ = ° 3. Substitution

4. 1 2m mm DAC

∠ + ∠= ∠

4. Angle addition

5. 45 45m DAC° + °

= ∠

5. Substitution

6. 90 m DAC° = ∠ 6. Simplify

7. DAC∠ is a right angle

7. Definition of a right angle

8. DA AC⊥

8. Definition of perpendicular lines

9. 3 4m m∠ = ∠ 9. Definition of angle bisector

10. 4 45m∠ = 10. Definition of congruent angles

11. 3 4m mm ECA

∠ + ∠= ∠

11. Angle addition

12. 45 45m ECA° + °

= ∠

12. Substitution

13. 90 m ECA° = ∠ 13. Simplify

14. ECA∠ is a right angle.

14. Definition of a right angle

15. EC AC⊥

15. Definition of perpendicular lines

16. AD

is parallel to .CE

16. Lines Perpendicular to a Transversal Theorem (Thm. 3.12)

Answers

Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A32

3.

4.

5. 7d = 6. 52

d =

7. 834

d = 8. 313

d =

3.4 Puzzle Time THE ADDER

3.5 Start Thinking

The lines 3y x= − and 2y x= + do not intersect; The line 5y x= − + intersects the line

3y x= − at the point ( )4, 1 and the line

2y x= + at the point 3 7, ;2 2

The angles are

right angles.

3.5 Warm Up 1.

2.

3.

STATEMENTS REASONS

1. , 1 3j ⊥ ∠ ≅ ∠ 1. Given

2. 2 390

m m∠ + ∠= °

2. Definition of complementary angles

3. 1 3m m∠ = ∠ 3. Definition of congruent angles

4. 2 190

m m∠ + ∠= °

4. Substitution

5. BED∠ is a right angle

5. Definition of a right angle

6. k m⊥ 6. Definition of perpendicular lines

STATEMENTS REASONS

1. m n⊥ 1. Given

2. 3∠ and 6∠ are complementary.

2. Definition of complementary angles

3. 3∠ and 4∠ are complementary.

3. Given

4. 4 6∠ ≅ ∠ 4. Congruent Complements Theorem (Thm. 2.5)

5. 4 5∠ ≅ ∠ 5. Vertical Angles Congruence Theorem (Thm. 2.6)

6. 5 6∠ ≅ ∠ 6. Transitive Property of Congruence (Thm 2.2)

y

x41−1

−2

4

y = x − 3

y = x + 2y = −x + 5

x

y

2

4

−2−6 6

y = 6x

x

y

2

4

−2−6 6

y = 4x + 2

x

y

41

2

−2

−1

y = x − 3

Answers

Copyright © Big Ideas Learning, LLC Geometry All rights reserved. Answers

A33

4.

5.

6.

3.5 Cumulative Review Warm Up 1. Multiplication Property of Equality

2. Subtraction Property of Equality

3. Reflexive Property of Equality for Real Numbers

4. Reflexive Property of Equality for Angle Measures

5. Transitive Property of Equality for Angle Measures

6. Symmetric Property of Segment Lengths

3.5 Practice A 1. ( )3.5, 1P 2. ( )0, 14.2P

3. perpendicular; Because

1 29 2 1,2 9

m m • = − = −

lines 1 and 2 are

perpendicular by the Slopes of Perpendicular Lines Theorem (Thm. 3.14).

4. neither; Because 1 24 5 1,5 4

m m • = =

lines 1

and 2 are neither parallel nor perpendicular.

5. 4 7y x= + 6. 6 9y x= − +

7. 1 83

y x= + 8. 3 8y x= −

9. 2 2 2.83≈ 10. 2 26 10.2≈

11. 7.5−

12. no; For a line with a slope between 0 and 1, the slope of a line perpendicular to it would be negative.

13. ( )5, 4

3.5 Practice B 1. ( )1.5, 3Q = 2. ( )0, 3Q =

3. neither; Because ( )1 2 1 12 ,6 3m m • = − = −

lines

1 and 2 are neither parallel nor perpendicular.

4. 6 10y x= − − 5. 1 114 4

y x= − +

6. about 4.5 7. about 4.4

8. Sample answer: 5, 1b c= =

9. a. The slope is 2 2, where 1 0.m m− ≤ <

b. The slope is 3 3, where 1.m m ≥

c. The lines are perpendicular; They are perpendicular by the Perpendicular Transversal Theorem (Thm. 3.11).

10. yes; Sample answer: The lines 12 and2

y x y x= = − have the same y-intercept

and the slopes are negative reciprocals.

11. 5 , 22

− −

3.5 Enrichment and Extension

1. 4 23 3

y x= − − 2. 18, 30a b= =

3. a. 3.62 b. 2.74 c. 3.62 17.8926y x= −

d. 0.276 1.412y x= −

x41−1

−4

2y

y = x − 223

1 4

2

x

y

−1

−2

x + 3y = − 43

y

1−4 −1

−2

3y = x + 2

x

Answers

Geometry Copyright © Big Ideas Learning, LLC Answers All rights reserved. A34

4. ; parallel: ; perpendicular:a ax by y xb b a

− = − =

5. 14, 102

k y x= − = − +

6. k can have any value, 2 5y x= −

7. a. ae db≠

b. , 0, 0a d b eb e

− = − ≠ ≠

8. a. Sample answer: ( ) ( ) ( )4, 4 , 4, 4 , 0, 2− b. Sample answer:

4, 4, 0, 4, 2x x x y y= − = = = =

c. ( ) ( ), , , , 0,2yy y y y −

3.5 Puzzle Time DROP THE S

Cumulative Review 1. 0 2. 0 3. 13

4. 40 5. 5− 6. 132

7. 25 8. 29 9. 12

10. 4− 11. 84− 12. 3

13. 29 14. 58− 15. 6−

16. 20− 17. 24− 18. 14

19. 16− 20. 19− 21.

13

22. 4 23. 5− 24. 7

25. 9− 26. 74− 27. 52

28. 53 29. 92− 30.

25

31. 78 32. 32− 33.

53−

34. a. 11 A.M. b. 6.5 in. c. 3 P.M.

35. a. about $42.92 b. about $9.90 c. about $1.41

36. 16x = 37. 8x = 38. 6x = −

39. 35x = − 40. 1x = − 41. 8x =

42. 9x = 43. 49x = − 44. 11x = −

45. 12x = − 46. 11x = − 47. 3x =

48. 3x = − 49. 1x = − 50. 6x = −

51. 5x = 52. 3, 4m b= = −

53. 4, 5m b= − = 54. 34 , 7m b= = −

55. 56, 3m b= − = 56. 1, 5m b= =

57. 1, 3m b= − = 58. 1, 1m b= − = −

59. 2, 9m b= − = 60. 3, 8m b= − =

61. 2, 5m b= = − 62. 5, 87

m b= =

63. 23, 4m b= − = − 64. 10x

65. a. 8 5 3− = b. 8 5.5 2.5− = c. Company A is 3 minutes faster. Company B is

2.5 minutes faster.

66. 9.4 67. 7.1 68. 20.4

69. 10.2 70. 16.4 71. 15.8

72. 16.3 73. 6.7 74. 18.4

75. 12.4 76. 7.8 77. 9.2

78. ( )2, 5.5− 79. ( )8, 1− 80. ( )3.5, 1− −

81. ( )2.5, 4 82. ( )2.5, 9.5− 83. ( )3, 0.5−

84. ( )5.5, 2− 85. ( )0.5, 7− 86. ( )5.5, 1.5−

87. ( )0.5, 1.5− − 88. ( )1.5, 0.5−

89. ( )0.5, 0.5−

90. a. each individual visit b. each individual visit c. 5 or more visits

Answers

Copyright © Big Ideas Learning, LLC Geometry All rights reserved. Answers

A35

91. a. $7.80 b. $9.70 c. 7 lb

92. 2 3y x= − 93. 3 27y x= − −

94. 1 12 25y x= + 95. 15 4y x= +

96. 14 2y x= − + 97. 8 93y x= +

98. 4 29y x= − + 99. 2 15 5y x= − +

100. 13 11y x= − 101. 12 3y x= − +

102. 19 10y x= − 103. 2 2y x= − +

104. 3 22y x= + 105. 7y = −

106. 13 3y x= − + 107. 46x =

108. 136x = 109. 28x =

110. 19x = 111. 35x = 112. 21x =

Chapter 4 4.1 Start Thinking

Translate the original triangle 2 units down; Each ordered pair for A B C′ ′ ′Δ contains y-coordinates that are two less than those of ;ABCΔ When identifying a translation, you can compare the x- and y-values to determine what happens if the figure is plotted.

4.1 Warm Up

1. 2.

( 2, 2)P′ − (0, 1)P′

3. 4.

(4, 0)P′ ( 4, 5)P′ −

5. 6.

(6, 0)P′ (4, 4)P′

4.1 Cumulative Review Warm Up 1.

1 2p q∠ ≅ ∠

GivenProve

x

y4

2

−2

−4

42−4 −2

P

P′

x

y4

2

−2

−4

42−4 −2

P

P′

x

y4

2

−2

−4

42−4 −2

P

P′

x

y

4

2

−2

42−4 −2

PP′

x

y4

2

−2

−4

4 6−2 PP′

x

y4

2

−2

−4

42 6−2P

P′

1

2

3q

p

t

STATEMENTS REASONS

1. p q 1. Given

2. 1 3∠ ≅ ∠ 2. Corresponding Angles Theorem (Thm. 3.1)

3. 3 2∠ ≅ ∠ 3. Vertical Angles Congruence Theorem (Thm. 2.6)

4. 1 2∠ ≅ ∠ 4. Transitive Property of Angle Congruence (Thm. 2.2)

x

y4

2

−2

42−4

A

C

B

B′C′

A′