Hi Shafiqah,

The surface area of a dome of radius $r$ units and height $h$ units is $2 \times \pi \times r \times h$ square units. There is a diagram in our response to an earlier question. This expression for the surface area does not include the floor. To include the area of the disk that forms the floor you would need to find its radius of this disk and calculate its area.

I hope this helps,
Penny

Yes; note that r is the radius of the full sphere, not of the floor of the dome.

The area of the floor is pi (r^2 - (r-h)^2) = pi h (2r-h).

Good Hunting!
RD