Comparing Ratios of Perimeters and Areas

Of

Similar Figures

Draw Similar Rectangles ABCD and EFGH whose lengths and widths are 16 and 12 and 12 and 9 respectively.

16

12

12

9

Compare the ratio of any two corresponding sides in simplest form.

16/12 = 4/3

Find the Perimeters of each rectangle and express their ratio

in simplest form.

56/42 = 4/3

Find the Areas of each rectangle and express their ratio in simplest

form.

192/108 = 16/9

Make an observation about the relationship among the three

simplified ratios.• Corresponding sides…..4/3

• Perimeters……………..4/3

• Areas…………………..16/9

The ratio of the perimeters is equal to the ratio of the corresponding sides.

The ratio of the areas is equal to the square of the ratio of the corresponding sides.