## Shaded Triangle

#### Problem

Find the area of the shaded square.

#### Solution

By splitting the diagram into triangles,

It can be seen that ^{4}/_{9} of the diagram is shaded. That is, ^{4}/_{9} × 18 = 8 units^{2}.

What is the perimeter of the shaded square?

Problem ID: 98 (Jan 2003) Difficulty: 2 Star