Answer:
350
Step-by-step explanation:
Multiply all the sides by each other. This is a triangular prism so the base, you divide by 1/2. So:
A = 7 * 10 * 10
A= 7 * 5 * 10.
(You divide the ten on the bottom)
7*5 = 35
35*10 = 350
240
The surface is the sum of the sides (all 4 equal) plus the base.
A = 4(1/2B * H) + B**2
A = 4((1/2 * 10) * 7) + 10 * 10
A = 4(5 * 7) + 100
A = 4 * 35 + 100
A = 140 + 100
A = 240
