Answer:
352 inches squared
Explanation:
The area of a triangle is 1/2 · base · height. There are 4 of the same triangles here, so it would be (1/2 · 8 · 18) · 4 to find the surface area of all 4 triangles, but you can't forget about the base. The area of a rectangle is length times width, so it would be 8 · 8. This means the formula for the entire surface area of this square pyramid is ((1/2 · 8 · 18) · 4) + (8 · 8). It can be simplified as follows:
((1/2 · 8 · 18) · 4) + (8 · 8)
((1/2 · 8 · 18) · 4) + 64
((4 · 18) · 4) + 64
(72 · 4) + 64
288 + 64
352