9514 1404 393
Answer:
800(9 +√2) cm² ≈ 8331.4 cm²
Step-by-step explanation:
The surface area of the pyramid is the sum of the areas of the base and triangular faces.
The base area is given by ...
A = 2(1 +√2)s² . . . . . where s is the length of one side
A = 2(1 +√2)(20 cm)² = 800(1 +√2) cm²
The lateral area is given by ...
A = (1/2)Ph . . . . . where P is the perimeter of the base and h is the slant height
A = (1/2)(8)(20 cm)(80 cm) = 6400 cm²
Then the total surface area of the pyramid is ...
SA = (800(1 +√2) +6400) cm² = 800(9 +√2) cm² ≈ 8331.4 cm²
