Review & Trapezoids. Properties of a Parallelogram A BC D 1. Opposite sides are parallel. 2 Opposite...

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Review & Trapezoids

Transcript of Review & Trapezoids. Properties of a Parallelogram A BC D 1. Opposite sides are parallel. 2 Opposite...

Review & Trapezoids

Properties of a ParallelogramA

B C

D1. Opposite sides are parallel.

2 Opposite sides are congruent.

3. Opposite angles are congruent.

5. Diagonals bisect each other

4. Consecutive angles are supplementary

YES, we’re going to review again, & again, & again…

Properties of a Rhombus

A

B C

D

1. Opposite sides are parallel.

2 Opposite sides are congruent.

3. Opposite angles are congruent.

5. Diagonals bisect each other

4. Consecutive angles are supplementary

6. 4 congruent sides

7. Diagonals of a rhombus bisect the angles

8. Diagonals of a rhombus are perpendicular (bisectors)

Properties of a Rectangle1. Opposite sides are parallel.

2 Opposite sides are congruent.

3. Opposite angles are congruent.

5. Diagonals bisect each other

4. Consecutive angles are supplementary

6. 4 congruent sides

7. Diagonals of a rhombus bisect the angles

8. Diagonals of a rhombus are perpendicular (bisectors)

9. 4 right angles

10. Diagonals are congruent

Properties of a Square1. Opposite sides are parallel.2 Opposite sides are congruent.

3. Opposite angles are congruent.

5. Diagonals bisect each other

4. Consecutive angles are supplementary

6. 4 congruent sides

7. Diagonals of a rhombus bisect the angles

8. Diagonals of a rhombus are perpendicular (bisectors)

9. 4 right angles

10. Diagonals are congruentIt has it ALL!!!

Practice with squares

A B

CD

BX=

AX =

DB =

AC =

8.5

8.5

17

17

AB=

BC=

12

12

X12

DX = 8.5

mAXB= mXAB=90 45

And now…Properties of Trapezoids

Definition of a Trapezoid-

exactly one pair of parallel sides

OR

A quadrilateral with:

Definition of a Trapezoid- Parallel sides are called BASES

base

base

base

base

leg leg leg leg

Other nonparallel sides are called LEGS

Definition of an ISOSCELES Trapezoid-

A trapezoid with Congruent legs

base

base

leg leg

AND Congruent base angles

Name the following for trapezoid RSTW

R S

W T

THE BASES:

THE LEGS:

ONE PAIR OF BASE ANGLES

RS, TW

RW, STR & S ; or T & W

Median of a Trapezoid

AM

D

BN

C

6

1410

The median of any trapezoid is parallel to the bases

The median is equal to half the SUM of the base lengths

6 14

A median (MN) is a segment connecting the midpoints of the legs

MN = 10

6 14 2010

2 2

6 14

2

>

>

(sum of bases)

(half of sum)

Examples – find the length of the median

5

19

11-x

21+x

10 5

3 3

44

12

16

7.5

24?

2

11-x+21+x?

2

10 5

2

EF=

m1=

m2=

m3=

m4=

m5=

2

78

3

1304

5

115

9

A B

CD

E F

12

50

102

78

50

130

Isosceles trapezoid?

Corr s

Base s

Same Side interior - supplementary

Corr s

Same Side interior - supplementary

EF=

m1=

m2=

m3=

m4=

m5=

2

51

34

45

1

11

6

EF

JK

L M

16

51

129

51

129

51

Isosceles trapezoid?