Note: Area of a circle = πr^{2}, where r is the radius of the circle.Example: What is the area of a circle whose diameter is 10 cm? Given: Diameter(d) = 10cm;
So, Radius(r) = Diameter/2 = 10/2 = 5cm Area of a circle: πr^{2} = π x 5^{2} = π x 25 = 25π sq cm