Question

The length of the arc of this semi-circle is 70m. What is the length of the radius?

Answer 1

r = 22.3m circa

Explanation:

We know that the perimeter of a circle can be calculated as follows:

p = 2
`\pi`r

So half of perimeter will be:

p/2 =
`\pi`r

We know that p/s = 70m, therefore:

r = 70m /
`\pi \\` = 22.3 m circa.