Find the length s of the circle of radius 75 meters subtended by the center angle 
radian.
Solution:-
A center angle is an angle whose vertex is at the center of a circle. The rays of a central angle subtend an arc on the circle. We have following theorem.
ARC LENGTH
For a circle of a radius r, a center angle of 
radian subtends an arc whose length s is
s = r
The value of r in the formula is 75 meters.
The value of in the formula is radian.
S(arc length) = 75 meters*radian
= 3 meters