geometry
posted by Anonymous .
"Triangle DEF is similar to triangle ABC, and the length of side DE is 6 cm. The length of side AB is 2 cm. If the area of triangle ABC is 5 square cm, what is the area of triangle DEF?

the ratio of areas of two similar shapes is proportional to the square of their corresponding sides
so area DEF/5 = 6^2 / 2^2 = 36/4 = 9/1
area DEF = 45