# The length of an arc of a circle is 50 cm and is subtended by a central angle of 2.5 radians. Find the radius of the circle.

1
by Skaya

2015-09-19T09:17:15+08:00
Central Angle : 2.5
Arc               : 50

We should find the Circumference
Reduce 50 over 360

Let us cross multiply

Divide both sides by 5.

Therefore, the circumference is 18.
That is not the answer, we still have some thing to do with this. We need the radius, not the circumference. But in finding the radius, circumference can be helpful.

C = 2πR
18 = 2πR

Divide both sides by two pi.

18 = 2πR
2π  =  2π

2.86478897565 = R

So therefore, the Radius is 2.86 cm