I'm going to build an earthbag dome structure and need to

Hi

Thanks for having a look at my thread.

I'm going to build an dome structure using the "earthbag" technique, and need to be able to work out the area of a dome.

I've found this equasion on wikipedia but as I don't know the principals cannot use it.

Dome (mathematics) - Wikipedia, the free encyclopedia

Can some one tell me in laymans terms how I can use a calculator to work out this equasion ?

Idially I need to use it to work out the diameter of a dome which has a volume of 10m3.

Thanks !

Mike