Counting squares

Counting squares diagram

A square centimetre is the area within a square with sides of length {1~cm}, as shown above.

We say that it has an area of {1~cm}^{2} ( {1~cm} squared).

Counting squares diagram

This rectangle contains six squares. Each of the squares has an area of {1~cm}^{2}, so the area of the rectangle is {6~cm}^{2}.

Question

By counting the squares, find the area of the following shapes:

a)

Counting squares diagram

b)

Counting squares diagram

a) {10~cm}^{2}

b) {8~cm}^{2}

Remember, there are six whole squares and four half squares in the triangle.