SA of a pyramid: 1/2ph + B
p = perimeter of base
h = slant height
B = area of base
The pyramid has a square base with each side being 3in, so multiply 3 in times 4 sides to find the perimeter of the base.
(3)(4) = 12 in
The diagram of the pyramid shows that the slant height is 7in.
Since the pyramid has a square base, to find the area of the base square one side of the square.
3in² = 9 in²
Now plug in the perimeter, slant height, and base into the formula for SA of a pyramid.
1/2(12)(7) + 9
42 + 9 = 51 in²
The surface area of the pyramid is 51 in².