10-4 Perimeters and Areas of Similar

Figures

Perimeters and Areas of Similar Figures

If the scale factor of two similar figures is , then• The ratio of their perimeters is • The ratio of their areas is

Problem 1: Finding Ratios in Similar Figures

The trapezoids are similar. The ratio of the lengths of corresponding sides is .a) What is the ratio (smaller to

larger) of the perimetersb) What is the ratio (smaller to

larger) of the areas?

Two similar polygons have corresponding sides in the ratio 5:7a) What is the ratio (larger to smaller)

of their perimeters?b)What is the ratio (larger to smaller)

of their areas?

Problem 2: Finding Areas Using Similar Figures

The are of the smaller regular pentagon is about 27.5 square cm. What is the best approximation for the area of the larger pentagon?

Problem 4: Finding Perimeter Ratios

The triangles are similar. What is the scale factor? What is the ratio of their perimeters?