The area of a circle is the product of pi and the square of its radius. It is expressed as:
Area = pi x r^2 where r = d/2
We calculate as follows:
Area = pi x r^2
Area = pi x (d/2)^2
Area = pi x (d^2 / 4)
Area = 3.14 x (9^2 / 4)
Area = 63.59 cm^2
Hope this answers the question. Have a nice day.