Area of rectangle 15 by 10 with a 5 by 2 rectangle cut out

Step by step

The question

Question: find the area of this shape: a 15 by 10 rectangle with a 5 by 2 hole cut out.

1 The whole and the hole

The whole shape would be a 15 by 10 rectangle.

A hole is cut out.

That part is not there any more.

So we take it away.

2 Area of each part

The whole rectangle: length times width.

15 times 10 is 150.

The hole is a 5 by 2 rectangle.

5 times 2 is 10.

3 Take away the hole

The area is the whole, take away the hole.

150 minus 10 is 140.

So the area is 140 square units.

4 Check

Let's check: put the hole back.

We should get the whole rectangle.

We get 150, the whole rectangle.

So the area is right!

Let's look back.

First: the whole and the hole.

Then: area of each part.

Then: take away the hole.

Last: check.