TACHS Math : Perimeter/Circumference

Study concepts, example questions & explanations for TACHS Math

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Example Questions

Example Question #1 : Perimeter Of Triangles, Squares, And Rectangles

Find the perimeter of a square with the following side length:

\(\displaystyle s=5\)

Possible Answers:

\(\displaystyle 20\)

\(\displaystyle 625\)

\(\displaystyle 5\)

\(\displaystyle 25\)

\(\displaystyle 10\)

Correct answer:

\(\displaystyle 20\)

Explanation:

Perimeters can be calculated by adding together the side lengths of a polygon. A square has four sides that are all the same length, therefore, we can write the following formula to solve for the perimeter.

\(\displaystyle P=s+s+s+s\)

We can rewrite this equation as the following:

\(\displaystyle P=4s\)

In these equations the variable, \(\displaystyle s\), represents side length.

Substitute the known side length and solve.

\(\displaystyle P=4\times5\)

\(\displaystyle P=20\)

Example Question #1 : Perimeter/Circumference

Find the circumference of a circle with the following radius:

\(\displaystyle r=4\)

Possible Answers:

\(\displaystyle 3.14\)

\(\displaystyle 4\pi\)

\(\displaystyle \pi\)

\(\displaystyle 16\pi\)

\(\displaystyle 8\pi\)

Correct answer:

\(\displaystyle 8\pi\)

Explanation:

In order to find the circumference of a circle we will use the following formula:

\(\displaystyle C=2\pi r\)

In this equation, the variable, \(\displaystyle r\), represent's the circle's radius.

Substitute in for the circle's radius.

\(\displaystyle C=2\times\pi \times 4\)

Simplify and solve.

\(\displaystyle C=8\pi\)

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