Answer:
c) 36√15 cm³
Step-by-step explanation:
We can compute the volume of the pyramid if we know the area of its base, and its height.
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A regular quadrilateral is a square. If one side of the square is 6 cm, its area will be ...
A = s² = (6 cm)² = 36 cm² . . . . area of the pyramid base
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Each triangular face will have a slant height that makes its area the same as that of the base.
A = 1/2bh
36 cm² = (1/2)(6 cm)h
(36 cm²)/(3 cm) = h = 12 cm . . . . . divide by the coefficient of h
The slant height of a face is the hypotenuse of a right triangle whose short leg is half the side length, and whose long leg is the height of the pyramid. If that height is represented by h, the Pythagorean theorem tells us ...
(6 cm/2)² +h² = (12 cm)²
h² = (144 -9) cm²
h = 3√15 cm . . . . . height of the pyramid
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The volume of the pyramid is given by ...
V = 1/3Bh . . . . . . base area B, height h
Using the values we found above, we compute the volume to be ...
V = (1/3)(36 cm²)(3√15 cm) = 36√15 cm³
