SSAT Upper Level Math : How to find the volume of a polyhedron

Study concepts, example questions & explanations for SSAT Upper Level Math

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Example Questions

Example Question #1 : How To Find The Volume Of A Polyhedron

Find the volume of a square pyramid that has a height of \(\displaystyle 9\) and a side length of \(\displaystyle 4\).

Possible Answers:

\(\displaystyle 42\)

\(\displaystyle 48\)

\(\displaystyle 60\)

\(\displaystyle 54\)

Correct answer:

\(\displaystyle 48\)

Explanation:

The formula to find the volume of a square pyramid is

\(\displaystyle \text{Volume}=(side)^2\frac{height}{3}\)

So plugging in the information given from the question,

\(\displaystyle \text{Volume}=4^2\frac{9}{3}=16\times3=48\)

Example Question #1 : How To Find The Volume Of A Polyhedron

Find the volume of a square pyramid with a height of \(\displaystyle 12\) and a length of a side of its square base of \(\displaystyle 3\).

Possible Answers:

\(\displaystyle 24\)

\(\displaystyle 60\)

\(\displaystyle 36\)

\(\displaystyle 48\)

Correct answer:

\(\displaystyle 36\)

Explanation:

The formula to find the volume of a square pyramid is

\(\displaystyle \text{Volume}=(side)^2\frac{height}{3}\)

So plugging in the information given from the question,

\(\displaystyle \text{Volume}=(3^2)\frac{12}{3}=9\times 4=36\)

Example Question #2 : How To Find The Volume Of A Polyhedron

Find the volume of a regular hexagonal prism that has a height of \(\displaystyle 10\). The side length of the hexagon base is \(\displaystyle 12\).

Possible Answers:

\(\displaystyle 660\sqrt3\)

\(\displaystyle 4320\sqrt3\)

\(\displaystyle 2160\sqrt3\)

\(\displaystyle 1440\sqrt3\)

Correct answer:

\(\displaystyle 2160\sqrt3\)

Explanation:

The formula to find the volume of a hexagonal prism is 

\(\displaystyle \text{Volume}=\frac{3\sqrt3}{2}(side)^2(height)\)

Plugging in the values given by the question will give

\(\displaystyle \text{Volume}=\frac{3\sqrt3}{2}(12^2)(10)=2160\sqrt3\)

Example Question #25 : Volume Of A Three Dimensional Figure

In terms of \(\displaystyle x\), find the volume of a regular hexagonal prism that has a height of \(\displaystyle 5\). The hexagon base has side lengths of \(\displaystyle 4x\).

Possible Answers:

\(\displaystyle 240x\sqrt3\)

\(\displaystyle 120x\sqrt3\)

\(\displaystyle 120x^2\sqrt3\)

\(\displaystyle 360x^2\sqrt3\)

Correct answer:

\(\displaystyle 120x^2\sqrt3\)

Explanation:

The formula to find the volume of a hexagonal prism is 

\(\displaystyle \text{Volume}=\frac{3\sqrt3}{2}(side)^2(height)\)

Plugging in the values given by the question will give

\(\displaystyle \text{Volume}=\frac{3\sqrt3}{2}(4x)^2(5)=120x^2\sqrt3\)

Example Question #3 : How To Find The Volume Of A Polyhedron

Find the volume of a regular tetrahedron with a side length of \(\displaystyle 12\).

Possible Answers:

\(\displaystyle 144\sqrt2\)

\(\displaystyle 1728\sqrt2\)

\(\displaystyle 288\sqrt2\)

\(\displaystyle 966\sqrt2\)

Correct answer:

\(\displaystyle 144\sqrt2\)

Explanation:

The formula to find the volume of a tetrahedron is

\(\displaystyle \text{Volume}=\frac{\sqrt2}{12}(side)^3\)

Plugging in the information given by the question gives

\(\displaystyle \text{Volume}=\frac{\sqrt2}{12}(12)^3=144\sqrt2\)

Example Question #4 : How To Find The Volume Of A Polyhedron

Find the volume of a regular octahedron that has a side length of \(\displaystyle 8\).

Possible Answers:

\(\displaystyle 100\sqrt2\)

\(\displaystyle \frac{512\sqrt2}{3}\)

\(\displaystyle 512\sqrt2\)

\(\displaystyle \frac{500\sqrt2}{3}\)

Correct answer:

\(\displaystyle \frac{512\sqrt2}{3}\)

Explanation:

Use the following formula to find the volume of a regular octahedron:

\(\displaystyle \text{Volume}=\frac{\sqrt2}{3}(side)^3\)

Plugging in the information from the question,

\(\displaystyle \text{Volume}=\frac{\sqrt2}{3}(8)^3=\frac{512\sqrt2}{3}\)

Example Question #5 : How To Find The Volume Of A Polyhedron

Find the volume of a regular octahedron that has a side length of \(\displaystyle 6y\).

Possible Answers:

\(\displaystyle 144y^3\sqrt2\)

\(\displaystyle 216y^3\sqrt2\)

\(\displaystyle 72y^3\sqrt2\)

\(\displaystyle 84y^3\sqrt2\)

Correct answer:

\(\displaystyle 72y^3\sqrt2\)

Explanation:

Use the following formula to find the volume of a regular octahedron:

\(\displaystyle \text{Volume}=\frac{\sqrt2}{3}(side)^3\)

Plugging in the information from the question,

\(\displaystyle \text{Volume}=\frac{\sqrt2}{3}(6y)^3=72y^3\sqrt2\)

Example Question #6 : How To Find The Volume Of A Polyhedron

Find the volume of a regular hexahedron with a side length of \(\displaystyle 14\).

Possible Answers:

\(\displaystyle \frac{2744\sqrt2}{3}\)

\(\displaystyle 196\)

\(\displaystyle 1372\sqrt3\)

\(\displaystyle 2744\)

Correct answer:

\(\displaystyle 2744\)

Explanation:

A regular hexahedron is another name for a cube.

To find the volume of a cube,

\(\displaystyle \text{Volume}=(side)^3\)

Plugging in the information given in the question gives

\(\displaystyle \text{Volume}=(14)^3=2744\)

Example Question #7 : How To Find The Volume Of A Polyhedron

Find the volume of a regular octahedron with side lengths of \(\displaystyle 9t\).

Possible Answers:

\(\displaystyle 243t\sqrt2\)

\(\displaystyle 243t^3\sqrt2\)

\(\displaystyle 729t^3\sqrt2\)

\(\displaystyle 81t^3\sqrt2\)

Correct answer:

\(\displaystyle 243t^3\sqrt2\)

Explanation:

Use the following formula to find the volume of a regular octahedron:

\(\displaystyle \text{Volume}=\frac{\sqrt2}{3}(side)^3\)

Plugging in the information from the question,

\(\displaystyle \text{Volume}=\frac{\sqrt2}{3}(9t)^3=243t^3\sqrt2\)

Example Question #8 : How To Find The Volume Of A Polyhedron

Find the volume of a prism that has a right triangle base with leg lengths of \(\displaystyle 3\) and \(\displaystyle 8\) and a height of \(\displaystyle 12\).

Possible Answers:

\(\displaystyle 432\)

\(\displaystyle 96\)

\(\displaystyle 288\)

\(\displaystyle 144\)

Correct answer:

\(\displaystyle 144\)

Explanation:

To find the volume of a prism, multiply the area of the base by the height.

\(\displaystyle \text{Area of Base}=\frac{3\times8}{2}=12\)

\(\displaystyle \text{Volume}=12\times height=12\times12=144\)

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