math

Coldplay and guest,

The volume of any prism is the area of the base times  by the height.

A cylinder is a circular prism.

The volume of a pyramid is 1/3 * the volume of prism (that it is a part of) and a cone is a pyramid 

Volume of cone =   1/3 * area of circular base  * height        units cubed

Hang on, that was volume, You want surface area ?

http://www.mathsteacher.com.au/year10/ch14_measurement/18_cone/20cone.htm

I'm not really sure, but my best guess would be to find the circumference of the base, then multiply it by height... Again, that is only a speculation...