Acircle has a radius of 48 millimeters. what is the central angle in radians, that intercepts an arc of length 36π millimeters?

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 

Ac equals 35 cm long