GED Math : Geometry and Graphs

Study concepts, example questions & explanations for GED Math

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Example Questions

Example Question #11 : Geometry And Graphs

Determine the diameter if the radius is \displaystyle \frac{2}{3}x-4.

Possible Answers:

\displaystyle \frac{4}{3}x-8

\displaystyle \frac{1}{3}x-2

\displaystyle \frac{4}{3}x-2

\displaystyle \frac{1}{3}x-8

Correct answer:

\displaystyle \frac{4}{3}x-8

Explanation:

The diameter is double the radius.

\displaystyle 2(\frac{2}{3}x-4) = \frac{4}{3}x-8

The answer is:  \displaystyle \frac{4}{3}x-8

Example Question #12 : Geometry And Graphs

Determine the diameter of a circle if the radius is  \displaystyle 2\frac{1}{3}.

Possible Answers:

\displaystyle \frac{25}{3}

\displaystyle 4\frac{1}{6}

\displaystyle \frac{13}{3}

\displaystyle \frac{7}{2}

\displaystyle \frac{14}{3}

Correct answer:

\displaystyle \frac{14}{3}

Explanation:

The diameter is twice the radius.

\displaystyle D= 2r

Convert the mixed fraction to an improper fraction.

\displaystyle D= 2(\frac{7}{3}) = \frac{14}{3}

The answer is:  \displaystyle \frac{14}{3}

Example Question #12 : Geometry And Graphs

Determine the diameter if the radius is \displaystyle \frac{1}{8}.

Possible Answers:

\displaystyle \frac{1}{16}

\displaystyle \frac{1}{32}

\displaystyle \frac{1}{64}

\displaystyle \frac{17}{8}

\displaystyle \frac{1}{4}

Correct answer:

\displaystyle \frac{1}{4}

Explanation:

The diameter is twice the radius.

Multiply the radius by two.

\displaystyle \frac{1}{8} (2) = \frac{2}{8} = \frac{1}{4}

The answer is:  \displaystyle \frac{1}{4}

Example Question #13 : Geometry And Graphs

What is the radius if the diameter of a circle is \displaystyle \frac{\sqrt3}{3}?

Possible Answers:

\displaystyle \frac{\sqrt{3}}{6}

\displaystyle \frac{2\sqrt3}{3}

\displaystyle \frac{\sqrt6}{3}

\displaystyle \frac{\sqrt6}{6}

\displaystyle \frac{3\sqrt{3}}{2}

Correct answer:

\displaystyle \frac{\sqrt{3}}{6}

Explanation:

The radius is half the diameter of a circle.

\displaystyle r=\frac{d}{2}

This is also similar to multiply diameter by one-half.

\displaystyle \frac{\sqrt3}{3} \times \frac{1}{2} = \frac{\sqrt{3}}{6}

The answer is:  \displaystyle \frac{\sqrt{3}}{6}

Example Question #13 : Geometry And Graphs

What is the radius with a diameter of \displaystyle \frac{\sqrt3}{2}?

Possible Answers:

\displaystyle \sqrt3

\displaystyle \frac{\sqrt3}{6}

\displaystyle \frac{\sqrt3}{4}

\displaystyle \sqrt6

\displaystyle \frac{\sqrt6}{4}

Correct answer:

\displaystyle \frac{\sqrt3}{4}

Explanation:

The radius is half the diameter.

Multiply the diameter by one-half.

\displaystyle \frac{\sqrt3}{2} \cdot \frac{1}{2} = \frac{\sqrt3}{4}

The answer is:  \displaystyle \frac{\sqrt3}{4}

Example Question #14 : Radius And Diameter

Find the radius of a circle with an area of \displaystyle 8\pi.

Possible Answers:

\displaystyle 4

\displaystyle 8\sqrt2

\displaystyle 2\sqrt2

\displaystyle \sqrt2

\displaystyle 4\sqrt2

Correct answer:

\displaystyle 2\sqrt2

Explanation:

Write the formula for the area of a circle.

\displaystyle A = \pi r^2

Substitute the area.

\displaystyle 8\pi = \pi r^2

Divide by pi on both sides.

\displaystyle \frac{8\pi }{\pi}=\frac{ \pi r^2}{\pi}

\displaystyle r^2 = 8

Square root both sides.

\displaystyle \sqrt{r^2 }= \sqrt{8}

\displaystyle r= \sqrt8 = 2\sqrt2

The answer is:  \displaystyle 2\sqrt2

Example Question #14 : Geometry And Graphs

Find the value of the diameter if the radius is \displaystyle 5\pi-2.

Possible Answers:

\displaystyle 5\pi -4

\displaystyle 10\pi -4

\displaystyle 10\pi -2

\displaystyle 5\pi +4

\displaystyle 10\pi +4

Correct answer:

\displaystyle 10\pi -4

Explanation:

The diameter is double the radius.

Multiply the quantity by two.

\displaystyle 2(5\pi-2) = 10\pi -4

The answer is:  \displaystyle 10\pi -4

Example Question #15 : Geometry And Graphs

Determine the radius if the diameter is \displaystyle \frac{\sqrt{2}}{3}.

Possible Answers:

\displaystyle \frac{1}{3}

\displaystyle \frac{\sqrt2}{2}

\displaystyle \frac{\sqrt2}{6}

\displaystyle \frac{2}{3}

\displaystyle 2\sqrt2

Correct answer:

\displaystyle \frac{\sqrt2}{6}

Explanation:

The radius is half the diameter.

Multiply the diameter by half.

\displaystyle \frac{\sqrt{2}}{3} \cdot\frac{1}{2}

The answer is:  \displaystyle \frac{\sqrt2}{6}

Example Question #981 : Ged Math

Determine the radius of the circle if the diameter is \displaystyle \frac{3\sqrt5}{7}.

Possible Answers:

\displaystyle \frac{3\sqrt5}{14}

\displaystyle \frac{6\sqrt5}{7}

\displaystyle \frac{3\sqrt{10}}{14}

\displaystyle \frac{3\sqrt{10}}{7}

Correct answer:

\displaystyle \frac{3\sqrt5}{14}

Explanation:

The radius is half the diameter.  To find the radius, multiply the diameter by half.

\displaystyle \frac{3\sqrt5}{7} \cdot \frac{1}{2} = \frac{3\sqrt5}{14}

The answer is:  \displaystyle \frac{3\sqrt5}{14}

Example Question #16 : Geometry And Graphs

Determine the radius of the circle if the diameter of a circle is \displaystyle \frac{3}{50}.

Possible Answers:

\displaystyle \frac{3}{100}

\displaystyle \frac{9}{100}

\displaystyle \frac{3}{50}

\displaystyle \frac{9}{50}

\displaystyle \frac{3}{25}

Correct answer:

\displaystyle \frac{3}{100}

Explanation:

The radius is half the diameter.

Multiply the diameter by one-half.

\displaystyle \frac{3}{50} \cdot \frac{1}{2} = \frac{3}{100}

The answer is:  \displaystyle \frac{3}{100}

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