Quest of Nine

The Book

Area of combined shapes

Look at this irregular shape.
Irregular area made of rectangles

We often need to find the area of an irregular shape, e.g how much carpet to order for a lounge or how much turf to buy for a new lawn.

Roll your mouse pointer over the shape to see that it is made up of three rectangles.

 

This irregular shape is a rectangle with another rectangle cut out of it.
Irregular area made of rectangles

Roll your mouse pointer over the shape to see how it is made.

Can you work out the area of these combined shapes?
Area = square
Check ittick

Not to scale