Item 12
1 answer:
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*see attachment for the diagram
Answer:
A. 178 units²
Step-by-step explanation:
Surface area of the figure = (surface area of the square pyramid + surface area of the square prism) - 2(base area of the square pyramid)
✔️Surface area of the square pyramid = s² + 2*s*l
Where,
s = side length of square base (w) = 6 units
l = slant height = ?
Use Pythagorean theorem to find l
l = √((w/2)² + y²)
l = √((6/2)² + 5²) = √(9 + 25)
l = √34
l ≈ 5.8 units
Surface area of the square pyramid = 6² + 2*6*5.8 = 105.6 units²
✔️Surface area of square prism:
SA = 2a² + 4ah
Where,
a = w = 6 units
h = x = 3 units
Substitute
SA = 2(6²) + 4*6*3
= 72 + 72
= 144 units²
✔️base area of the square pyramid = s²
s = w
Base area = 6²
Base area = 36 units²
✅Surface area of the figure = (surface area of the square pyramid + surface area of the square prism) - 2(base area of the square pyramid)
Surface area of the figure = (105.6 + 144) - 2(36)
= 249.6 - 72
= 177.6
≈ 178 units²
