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Find the volume of the cone. Use 3.14 for pi

Round your answer to the nearest tenth if needed.

(Hint #1: the diagram displays the slanted height, NOT the vertical height).

(Hint #2: use properties of a 45-45-90 degree triangle to find the vertical height. Round this to the nearest tenth.)

Find the volume of the cone. Use 3.14 for pi Round your answer to the nearest tenth-example-1

1 Answer

4 votes

Answer:

1329.3 yd³

Explanation:

You want the volume of a cone with an offset peak such that the angle of elevation of the peak from one side of the base is 45°, and that slant height is 18 yards. The diameter of the base is 20 yards.

Height

The ratio of sides in a 45°-45°-90° triangle is 1 : 1 : √2. That is, the height of the cone is ...

h = (18 yd)/√2 ≈ 12.7 yd . . . . . rounded height value

Volume

The volume of the cone is given by ...

V = (π/3)r²h

The radius is half the diameter, so is ...

r = (20 yd)/2 = 10 yd

Then the volume is ...

V = (3.14/3)(10 yd)²(12.7 yd) ≈ 1329.3 yd³

The volume of the cone is about 1329.3 yd³.

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Additional comment

If the "pi button" on the calculator is used, and no intermediate rounding of computation results is done, the volume is computed as 1332.9 yd³.

Loose granular material rarely has an angle of repose greater than 45°. The angle on the other side of the cone is about 60.3° relative to the base.

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Find the volume of the cone. Use 3.14 for pi Round your answer to the nearest tenth-example-1
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