What is the lateral area of a regular pentagonal pyramid that has a slant height of 18 in. and a base side length of 9 in.?

Question

405 in.^2
810 in.^2
81 in.^2
162 in.^2

I don't know how to do this:/ Please help?

Answer 1

the slant height is the height of the triangles that make up the sides of the pyramid
the base of the triangles is the base side length
pentagonal means five triangular sides with a height of 18 and a base of 9
find the areas and add them up (or find one and multiply by 5)

Answer 2

Thanks, I know its 405 now:)