How do you find the area of a pyrimid?

Answer 1

The base is a polygon with n sides.
Assume we know the side length, s, and the apotheme, a.
The area of the base is then
nas/2.

The slanted sides are triangles with base s and slant height h.
The area of the n slanted triangles are then
nhs/2

Thus, the total area of a pyramid with n sides is
A=nas/2+nhs/2=ns(a+h)/2

Answer 2

The surface area of a square-based pyramid is the sum of
the area of the 4 congruent isosceles triangles + area of the base

(you will have to decide if the question includes the base area from the wording of the question)