Question

Given the circle above, what is the length of radius r to the nearest tench of an inch? Use 3.14 for pi.

Answer 1

3.1 in

Explanation:

for the given circle the following ratios are equal

`(arc)/(circumference)` =
`((5\pi )/(12) )/(2\pi )`, hence

`(4)/(2\pi r)` =
`((5\pi )/(12) )/(2\pi )`

cross- multiply

2πr ×
`(5\pi )/(12)` = 8π ( divide both sides by 2π )

`(5\pi )/(12)` r = 4

multiply both sides by 12 and divide by 5π

r =
`(12(4))/(5\pi )` = 3.1 ( to the nearest tenth )