How do you find the length of the red line segment inside the cube?

5 in

In this lesson you will learn how to apply the Pythagorean Theorem to three dimensional

figures by creating right triangles.

Let’s ReviewLet’s Review

Pythagorean Theorem

a2 + b2 = c2

a

b

c

leg2 + leg2 = hypotenuse2

leg

leg hypotenuse

Let’s ReviewLet’s Review

LengthWidthHeight

Edge

Let’s ReviewA Common Mistake

x

y3 ft

7 ft

6 ft

Let’s ReviewCore Lesson

5 in

5 in

leg2 + leg2 = hypotenuse2

52 + 52 = x2

50 = x2

=

7.1 = x

5 in

7.1 in

5 in

25 + 25 = x2

Let’s ReviewCore Lesson leg2 + leg2 = hypotenuse2

5 in

7.1 in

52 + 7.12 = x2

25 + 50.4 = x2

75.4 = x2

=

8.68… = x

x

8.7 = x

In this lesson you have learned how to apply the Pythagorean Theorem to three dimensional

figures by creating right triangles.

Let’s ReviewGuided Practice Find the length of the red line segment inside the rectangular prism.

3 ft7 ft

4 ft

Let’s ReviewExtension Activities

Find the value of x in the diagram below.

x

8 ft

4 ft

3 ft

Let’s ReviewExtension Activities

Find the length of the red line segment inside the cube.

8 cm

Let’s ReviewExtension ActivitiesFind the length of the red line segment inside the rectangular prism.

3 ft

10 ft

2 ft

Let’s ReviewQuick QuizFind the length of the line segment inside the rectangular prism.

4 ft9 ft

6 ft

Let’s ReviewQuick QuizFind the length of the red line segment inside the cube.

4 cm