Answer:
254.6 ft3 F
Explanation:
To find the volume of the pyramid, first calculate the area of the base.
As the pyramid is the regular triangular pyramid, the base is an equilateral triangle.
To find the area of the equilateral triangle, calculate the length of the height.
Since the triangle is equilateral, each angle in the triangle equals 60°.
The height forms a 30°- 60°- 90° triangle. One leg of this triangle is equal to half of the side of the large triangle, or 7 ft. The other leg of the triangle is equal to 73‾√ ft by the 30°- 60°- 90° Triangle Theorem.
Therefore, the length of the height of the triangle is 73‾√ ft.
To find the area of the base of the pyramid, B, use the formula for the area of a triangle, B=12bh.
Substitute 14 for b and 73‾√ for h.
B=12⋅14⋅73‾√
Simplify.
B=493‾√ ft2
To find the volume of the pyramid, use the formula for the volume of a pyramid, V=13Bh.
Substitute 493‾√ for B and 9 for h.
V=13⋅493‾√⋅9
Simplify.
V=1473‾√
Use a calculator to approximate.
V≈254.6 ft3
Therefore, the volume of the regular triangular pyramid is about 254.6 ft3.