Example 1 For each pair of similar figures, find the perimeter of the second figure.
11
18 mm
12 mm1=^ 38 mm^1 =^? mm^2.5 ft
2 ft1= 21 ft1=? ftExample 2 3. DIGITAL PHOTOGRAPHY Julie is enlarging a digital photograph on her
computer. The original photograph is 5 inches by 7 inches. If she enlarges
it 1.5 times, what will be the area, in square inches, of the new image?= Step-by-Step Solutions begin on page R1.
Extra Practice begins on page EP2.Example 1 For each pair of similar figures, find the perimeter of the second figure.
4.3 cm 4 cmP = 18 cmP =? cm 5.
8.4 in. 6.3 in.1 = 19.4 in. 1 =? in.- INVITATIONS For your birthday party, you make a map to your house on
a 3-inch-wide by 5-inch-long index card. What will be the perimeter of
your map if you use a copier to enlarge it so it is 8 inches long?
Example 2 7. MODEL TRAINS Craig is making
a model version of his neighborhood
that uses model trains. The ratio of the
model train to the actual train is 1 : 64.
His neighborhood covers an area of
200,704 square feet. What will be the
area of the model neighborhood?- ADVERTISING A company wants to reduce the size of its logo by one fourth
to use on business cards. If the area of the original logo is 4 square inches,
what is the area of the logo that will be used on the business cards?
B 99 GOLF Theo is constructing a miniature putting green in his backyard.
He wants it to be similar to a putting green at the local golf course,
but one third the size. The area of the putting green at the golf course
is 1,134 square feet. What will be the area of the putting green Theo
constructs?- LOGOS Mr. James is enlarging a logo for printing on the back of a T-shirt.
He wants to enlarge a logo that is 3 inches by 5 inches so that the
dimensions are 3 times larger than the original. How many times as
large as the original logo will the area of the printing be?
Lesson 3B Similarity and Proportional Reasoning 301293_303_C05_L3_895130.indd 301 12/29/09 1:10 PM