This worksheet is about finding the areas of circles, given their diameters.

You must learn this important formula for a circle of radius, r :

Area of a circle = π r^{2}

Remember that the radius is HALF the diameter.

**Example**

Find the area of a circle of diameter 12 cm.

**Answer**

First work out the **radius**, which will be 12 ÷ 2 = 6 cm

**Area = π r ^{2}** = π x 6

^{2}= π x 36 =

**113.1**cm

^{2}(1 dp)