1. Similar
Figures
LESSON 7-4

2. In a proportion, the _____________________ are equal.
Similar Figures
LESSON 7-4
Similar Figures
____________________________________ have the same shape but not necessarily the same size.
Similar Polygons
If two polygons are ______________________________, then corresponding angles are congruent and the lengths of corresponding sides are in proportion. 
The symbol ___________ means “is similar to.”
REMEMBER:
Cross Products
In a proportion, the _____________________ are equal.

3. Is rectangle ABCD similar to rectangle RSTU? Explain why or why not.
Similar Figures
LESSON 7-4
Is rectangle ABCD similar to rectangle RSTU? Explain why or why not.
First,
check to see if corresponding angles are congruent.
∠ A ≌ ∠ R      ∠ B ≌ ∠ S
∠ C ≌ ∠ T     ∠ D ≌ ∠ U
All right angles are 90°.

4. Next, check to see if corresponding sides are in proportion.
Similar Figures
LESSON 7-4
Next, check to see if corresponding sides are in proportion. AB RS DA UR
AB corresponds to RS. DA corresponds to UR. 6 48 3 24
Substitute.
6 • • 3
Write the cross products.
144 = 144
Simplify.
The corresponding sides are in proportion, so rectangle ABCD is similar to rectangle RSTU.

5. Similar Figures
LESSON 7-4
A stonemason’s sketch of a carving to be made on a building includes the letter “E” shown below. If the width of the actual letter in the arrangement is 22 in.,
what is the height?
Set up a proportion.
2.75 in.
5 in.
22 in. x =
2.75 • x = 5 • 22
Write the cross products.
Simplify.
2.75 x = 110
Divide each side by 2.75.
2.75x
2.75
110 =
x = 40
Simplify.
The height of the letter is 40 inches.

6. Similar Figures RST ~ PSU. Find the value of d. Write a proportion. 14
LESSON 7-4
RST ~ PSU. Find the value of d.
Write a proportion. 14 d 12 21 =
12 • d = 21 •14
Write the cross products.
Simplify.
12d = 294
Divide each side by 12.
12d 12
294 =
d = 24.5
Simplify.
The value of d is 24.5.