Radian measure by diving the length of an arc by the radius of the circle. Therefore, 1 radian is the angle subtended to the center of a circle by an arc length equivalent to the radius of a circle.
radius is 48 millimeters and the length of an arc is 36π millimeters
Hence, radians =S/r
= 36 π/48 if we take π as 3.14
= 36 ×3.14 /48
= 2.355 radians
