Question

What is the radius of a circle with a circumference of fourteen point one three meters? Use three point one four for pi and show your work.

Answer 1

im think its 2.25

Answer 2

Circumference is,
\(C=2\pi r^2\)
\(C=14.13m\)
\(\pi=3.14\)

So we have,
\(14.13=2(3.14)(r^2)\)

Solve for r.
\(14.13=6.28r^2\)
\(2.25=r^2\)
\(r=\sqrt{2.25}=1.5\)

Answer 3

so its 1.5?

Answer 4

It is indeed. You were almost there, you just needed to take the square root to get r, not r^2.

Answer 5

oh but im trying to fin the radius
why od i do square root

Answer 6

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Answer 7

Because the formula for circumference is,
\(C=2\pi\color{red}{r^2}\)
Radius is \(r\) not \(r^2\).
So to get rid of the square, you take the root of it.

Answer 8

the formula is 2*3.14*r

Answer 9

Oh, oops it is indeed.
In that case, it is \(\color{blue}{2.25}\)

Answer 10

so i was right right?

Answer 11

anyways can you show me how to work that

Answer 12

\(C=2\pi r\)

\(C=14.13m\\
π=3.14\)

\(14.13=2(3.14)r~~~\color{green}{\text{distribute}}\\
14.13=6.28r~~~\color{green}{\text{divide by 6.28}}\\
r=2.25\)

Answer 13

alrite thx