3 9 56 35 4 12 28 26

3 9 56 35 4 12 28 26

A letter 36 inches tall on a billboard would be 216 picas, or 2592 points. The first letter in this paragraph is 12 points.

The ratio formed by the corresponding sides is the scale factor.

Additional Example 1: Using Scale Factors to Find Missing Dimensions To find the scale factor, divide the known measurement of the scaled picture by the corresponding measurement of the original picture. 0. 15 Then multiply the width of the original picture by the scale factor. 2. 1 The picture should be 2. 1 in. wide.

Try This: Example 1 To find the scale factor, divide the known measurement of the scaled painting by the corresponding measurement of the original painting. 0. 25 Then multiply the width of the original painting by the scale factor. 14 The painting should be 14 in. wide.

Additional Example 2: Using Equivalent Ratios to Find Missing Dimensions Set up a proportion. 4. 5 in. 3 ft

Additional Example 2 Continued 18 4. 5 The third side of the triangle is 4 ft long.

Try This: Example 2 Set up a proportion. 18 ft 4 in.

Try This: Example 2 Continued 96 18 The third side of the triangle is about 5. 3 in. long.

Additional Example 3: Identifying Similar Figures Since three figures are all rectangles, all the angles are right angles. So the corresponding angles are congruent.

Additional Example 3 Continued 10 4 5 2 20 = 20 10 12 4 5

Try This: Example 3 Since three figures are all rectangles, all the angles are right angles. So the corresponding angles are congruent.

Try This: Example 3 8 4 6 3 24 = 24 8 5 4 2

Lesson Quiz