Answer:
418ft²
Explanation:
Find the surface area of both triangle shaped sides.
8 * 12 = 96
96 / 2 = 48 (surface area of one triangular side)
48 * 2 = 96
Find the surface area of both square shaped sides.
10 * 10 = 100
100 * 2 = 200
Find the surface area of the rectangular base side.
12 * 10 = 120
Add everything together.
96 + 200 + 120 = 418
Best of Luck!