



 
Hi Charlie, The expression you have for the surface area of a dome is correct (except you misses a parenthisis). It is
where h is the dome height. This simplifies to
If, for example, h = r so that the dome (light blue) is half of the sphere then the surface area of the dome is 2 π r^{2} square units, twice the area ofthe base (dark blue). If h is very small then the area of the cap can be much smaller than the area of the base. I hope this helps,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 