7th Grade Math

Lesson 3A Similarity and Proportional Reasoning 297

Example 3 The triangles are similar. Write a proportion and solve the problem.

9. BASKETBALL What is the height 10. TREES How tall is the tree?
   of the basketball hoop?

4.5 ft

Y ft

3 ft

18 ft

4 ft

Y ft

3 ft

0.5 ft

B 1111 GRAPHIC NOVEL Refer to the graphic novel frame below for Exercises

a and b.

Our map has

shown to be

very handy.

Review the

map at the

start of the

chapter one

more time.

Our m

shown

very ha

Review

map at

start

chapt

more t

a. If the red line represents the path they took, how far have Raul, Caitlyn,

and Jamar traveled since they left the lake?

b. What will be their total distance by the time they return to the cabin?

12. FURNITURE A child’s desk is made so that it is a replica of a full-size adult
    desk. Suppose the top of the full-size desk measures 54 inches long by
    36 inches wide. If the top of the child’s desk is 24 inches wide and is
    similar to the full-size desk, what is the length?

C 13. CHALLENGE Determine whether each statement is true or false. Explain.

a. Any two squares are similar. b. Any two rectangles are similar.

14. E WRITE MATH Write a real-world problem that could be solved using
    proportions and the concept of similarity. Solve the problem.

293_303_C05_L3_895130.indd 297 12/29/09 1:10 PM