7th Grade Math

296 Proportions and Similarity

Example 1 1. Which rectangle below is similar "#

% 6 $

4

to rectangle ABCD?

'

4 (

&

)

2

6

9

1

3

2

4

Example 2 ALGEBRA Find the value of x in each pair of similar figures.

2.

9

;

67

8

7 m :

x m

4 m

20 m

3.

&

#$

%

'(

"

)

39 mm

x mm

13 mm

15 mm

Example 3 4. SHADOWS A flagpole casts a

20 ft

x ft

5 ft

6 ft

20-foot shadow. At the same time,

Humberto, who is 6 feet tall, casts

a 5-foot shadow. What is the height

of the flagpole? Assume the

triangles are similar.

= Step-by-Step Solutions begin on page R1.

Extra Practice begins on page EP2.

Example 1 55 Which triangle below is similar to  FGH?

'

( )

2

5

1

. /
4

1

" #

$

4

10

6. Which parallelogram below is similar to  HJKM?

9

; :

8

10

(^16)
(^34)
6 5
16
20
Example 2 ALGEBRA Find the value of x in each pair of similar figures.
7. (^2)
01
3 4
5
6 mi
30 mi
5 mi
x mi
8.
4 7
5 6
14 cm
x cm
8 ;
9 :
14 cm
28 cm

• ,
  )
  .
  12
  15
  293_303_C05_L3_895130.indd 296 12/29/09 1:09 PM