Question

A circle has a circumference of 7.850 units. What is its radius?

Answer 1

`\bf \textit{circumference of a circle}\\\\ C=2\pi r~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ C=7.850 \end{cases}\implies 7.850=2\pi r\implies \cfrac{7.85}{2\pi }=r\implies 1.25\approx r`

Answer 2

1.25 = r

Explanation:

The formula for circumference is given by

C = 2*pi *r

We know the circumference is 7.85

7.85 = 2 * 3.14 *r

7.85 = 6.28 *r

Divide each side by 6.28

7.85 /6.28 = 6.28*6/6.28

1.25 = r