The illustration below shows an angle whose vertex is placed

The illustration below shows an angle whose vertex is placed at the center of a circle that has a radius length r meters. The angle has a measure of theta radians, and its rays cut off an arc length of s meters. Define a formula for the angle measure, theta, in terms of the arc length and radius length. theta = b. The angle measure, theta, in radians is ... equal to the number of radius lengths that would mark off the are length, s. the fraction that r is of the total are length s the relative size of the arc length with respect to the circumference of the circle (both measured in meters). the openness of two rays, r meters long compared to the circumference in meters. the arc length measured in units of the radius. the relative size of the arc length with respect to the radius of the circle (both measured in meters). found by multiplying two rays of length r meters by a distance of s meters.

Solution

theta= s/r where s is the arc length and r is the radius.

As we can say that theta is the rario of arc length and ratio which can also be defined as the relative size of arc length with repect to radius of circle.