Area of a Circle

Finding the Area

This is a circle.

The radius is 3.4cm.

To find the area of the circle, we need this formula:

$$A = \pi r^2$$

Substitute the known values in:

$$A = \pi (3.4)^2$$

Simplify:

$$A = \pi × 11.56$$

Tidy up:

$$A = 11.56 \pi$$

If we wanted to leave the answer in terms of pi, that would be it.

If we want an actual value, we can work it out:

$$A = 36.3168110755 $$

Round to a suitable number of decimal places. Let’s say 2.

$$A = 36.32 $$

And finally, put the units in…

$$A = 36.32 cm^2 $$