Area of a circle formula

Area of a Circle (A) = π.r2 Where r- is the radius of the circle Alternate formula A = π.d2/4 Where d- is the diameter of the circle. An example to compute area using the area of a circle formula Find the area of a circle with radius as 5 cm. Solution: Given radius (r) = 5cm Area of a circle formula is:

Area = π.r²

Here r =5cm therefore we have π.5.5 = 78.5398 sq cm

If diameter of a circle is given we can either compute radius from diameter and utilize the same formula as above or use the diameter version of the area of the circle formula

Area = π.d²/4

The Area of a circle with diameter as 8cm is:

Apply diameter version of the Area of the circle formula pi.d²/4, we get

π.8.8/4 = 50.265 sq cm