9514 1404 393
Answer:
144 m²
Step-by-step explanation:
The total surface area is the sum of the areas of the four triangular faces.
Three of them have a base of 10 and a height of 6.7. The fourth has a base of 10 and a height of 8.7. Here, we'll show the sum in one expression, so we can do some simplification.
A = ∑(1/2)bh = (1/2)(10)(6.7) +(1/2)(10)(6.7) +(1/2)(10)(6.7) +(1/2)(10)(8.7)
= (1/2)(10)(3·6.7 +8.7) = 5(28.8) = 144 . . . . square meters
