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26 votes
26 votes
Mad math for pi, I have no clue how to do this!!

Mad math for pi, I have no clue how to do this!!-example-1
User Elliot Larson
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1 Answer

13 votes
13 votes

To calculate the volume of this figure, we just have to find the volume of the hemisphere and the volume of the cone, then sum them up.

The volume of a hemisphere (the half of a sphere) is given by the formula:


V=(2)/(3)\pi r^3

Where r is the radius.

The volume of a cone is given by the formula:


V=(1)/(3)\pi r^2h

Where h is the height of the cone.

From the figure we have:

r = 5.3in

h = 9 in

Then, when we substitute these values into the above formulas, we get:

For the hemisphere:


V=(2)/(3)\pi r^3=(2)/(3)*3.14*(5.3)^3=311.6

The volume of the hemisphere is 311.6in^3

For the cone:


V=(1)/(3)\pi r^2h=(1)/(3)*3.14*5.3^2*9=264.7

As mentioned, the volume of the whole figure is the sum of the volume of the cone and the volume of the hemisphere, then, the volume of the figure is:

V=311.6in^3 + 264.7in^3 = 576.3in^3

Then, the correct answer is option A

User Vlad Bezden
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3.1k points