Question

A regular square pyramid has a height of 2 and lateral edges of length 10. What is the lateral area and total surface area of the pyramid?

Answer 1

If the diagonal of the base has length 2d, then
d^2 + 2^2 = 10^2
The sides of the base have length 2b, where
b^2 + b^2 = d^2
Each triangular face has slant height h, where
b^2 + 2^2 = h^2
Now you can find the area of the base, and the area of each face.