### Home > MC2 > Chapter 9 > Lesson 9.3.3 > Problem9-113

9-113.

One of the triangles below is a reduction of the other. Find each of the missing parts listed below.

1. Find the length of side BC.

What is the scale factor between the two triangles?

$\frac{120}{15} = \frac{160}{x}$

$x = 20$ cm

2. Find the length of side AB.

See (a).

3. Find the ratio of the areas of the two triangles.

If the ratio of the perimeters is the scale factor, the ratio of the areas is the scale factor squared.

$\frac{1}{64}$