maths problem

[b-grrrlie]

I haven't been using maths for ages so I've totally forgotten how to count area of a circle. Diameter is 220 cm.
You schoolkids and mathgeniuses, help me!

[GreenEarthAl]

Area = pi * r squared.

Area = 3.1415 * (110cm squared).

Area = 38013.239

[b-grrrlie]

Thank you!
I knew pi was there somewhere...