The image above is a circle.

To compute the area of a circle, one essential parameter is needed and this parameter is the **radius of a circle** (r). You can also use the **diameter of a circle** to compute the area of a circle (d).

The formula for calculating the area of a circle is:

A = πr^{2}

Where:

A = Area of a circle

r = Radius of a circle

Let’s solve an example:

Find the area of a circle where the radius of a circle is 6 cm.

This implies that;

r = Radius of a circle = 6 cm

A = πr^{2}

A = 3.142 (6)^{2}

A = 3.142 (36)

A = 113.10

Therefore, the **area of a circle** is **113.10 cm ^{2}**

**Calculating the Area of a Circle using the Diameter of a Circle.**

The formula is A = ^{πd}^{2}/_{4}

Where;

A = Area of a circle

d = Diameter of a circle

Let’s solve an example:

Find the area of a circle where the diameter of the circle is 7 cm.

This implies that;

d = Diameter of a circle = 4 cm

A = ^{πd}^{2} / _{4}

A = ^{3.142 (4)}^{2} / _{4}

A = ^{3.142 (16)} / _{4}

A = 3.142 (4)

A = 12.57

Therefore, the **area of a circle with diameter** **given **is **12.57 cm ^{2}**