DO NOW Wednesday, November 6, 2013

What are we going to do?

CFUWe will use the Pythagorean Theorem1 to calculate the sides of Right Triangles2.

Learning Objective

Activate Prior Knowledge

Tuesday, November 5, 2013 Name: ________________________ Per: __

1

Vocabulary

2 Special Triangles that contain one Right (90 degree) angle.

Vocabulary

Two Dimensional Shapes come in many sizes and numbers of sides.

Triangles have exactly three sides.

Triangles add up to 180 degrees.

Special triangles have unique characteristics, such as Right triangles.

What else do you know about triangles?

Concept Development

Right Triangles contain two legs and a hypotenuse.• The Hypotenuse1 is the side of the triangle across from the right angle

(ALSO: it is the longest side).• There are two legs2 which can be the same size or different sizes. They are

shorter than the hypotenuse

How many legs does a right triangle have?

CFU

2 Two shorter sides of a Right Triangle.

Vocabulary

1 The longest side of a Right Triangle across from the right angle.

Vocabulary

What part of the triangle is the hypotenuse across from?

CFU

Side Length PR or RP

FG is a Hypotenuse

PQ or QP and QR or RQ

GH is a leg

There are 2 legs.

The hypotenuse is across from the right angle.

Concept Development

In the triangles shown, what does the letter c represent?

CFU

162 122 162

144 256

400

20 -20

20 -20

20Can a Hypotenuse or Leg length ever be negative?

CFU

Concept Development

What is the formula for the Pythagorean Theorem?

CFU

82 152

64 225

289

289

17 -17

17 -17

17

Concept Development

49

625

13 in.HINT: Use the Pythagorean Theorem.

a2 + b2 = c2

52 + 122 = 132

25 + 144 = 169

Equation is balanced, therefore this is a right triangle.

Skill Development/Guided Practice

32 + 42 = c2

9 + 16 = c2

25 = c2 c = 5

62 + 82 = c2

36 + 64 = c2

100 = c2 c = 10

Skill Development/Guided Practice

a2 + b2 = c2

52 + 122 = c2

25 + 144 = c2

169 = c2

= c

13 = c

169

a2 + b2 = c2

62 + 82 = c2

36 + 64 = c2

100 = c2

= c

10 = c

100

c

c

What is the diagonal line across from the right angle called in a right triangle?

CFU

Relevance

Television are advertised by the length of their diagonal screen size. Example: A 27 inch TV has a diagonal (hypotenuse) measure of 27 inches.

Crazy Eddie’s Electronics in San Jose is having a Veteran’s Day Sale on all TV’s that are 40 inches and larger.

Is the TV to the left going to be on sale? Explain your reasoning.

How can you use the Pythagorean Theorem to explain the dimensions of the TV?

What is the length of the diagonal on the TV shown above?

242 + 322 = c2

576 + 1024 = c2

1600 = c2

= c 40 = c1600

YES, the TV will be on sale because it is at least 40 inches.

What did you learn today about the Pythagorean Theorem? (Pair-Share) Use words from the word bank.

Summary Closure

Word Bank

Skill Closure

Leg HypotenusePythagorean Right Triangle

How can we prove whether this triangle is a Right Triangle or Not?

a2 + b2 = c2

32 + 42 = c2

9 + 16 = c2

5 = c

If a2 + b2 = c2, then you have proven a right triangle.

Independent Practice

Independent Practice

USE THIS SPACE FOR ANY SCRATCH WORK. WHICH TERM IS A, WHICH IS B, WHICH IS C?

The triangle to the right is for a reference only. You need to draw your own, and label the lengths of the sides.