Area Of A Circle Formula If you know the radius r r in whatever measurement units mm cm m inches feet and so on use the formula p r 2 to find area A A. 00001131 square kilometers km² 1131 square meters m² 1131 10 6 square centimeters cm². The formula for the area of a circle is p x radius2 but the diameter of the circle is d 2 x r 2 so another way to write it is p x diameter 22.
Area A pi x radius x radius.
Watch this tutorial to see how its done. Also if we know the circumference of the circle then we can find the area of circle. Divide the diameter in half. C p o.