The ratio of corresponding side lengths are 1:3. the perimeter of the smaller triangle is 36 inches. the area of the smaller triangle is 54 square inches. What is the perimeter and area of the larger figure?

1 Answer
Jul 16, 2017

See explanation.

Explanation:

The ratio of the side lengths is 1:3, so all sides of the larger triangle are 3 times larger than the sides of the smaller one. Therfore the perimeter of the larger triangle is also 3 times larger. It is: 3×36=108 inches.

There is a theorem which says:

The ratio of areas of a similar figures equals the square of the ratio of the similarity.

In the example the ratio of the similarity is 3, therfore the larger triangle has 32=9 times larger area:

A2=9×A1=9×54=486 square inches