To find the arc of a circle, divide the angle subtended at the center of the arc by 360 degrees, then multiply the answer by the circumference of the circle. You need to know the value of pi and must have a protractor to complete this task.Continue Reading
Using a protractor, measure the angle subtended at the center of the circle by the arc. When measuring, be sure to align the baseline of the protractor with the radius. To get an accurate value, repeat the measurement.
Multiply by pi, which is 22/7 by 2, and further multiply the answer by the radius of the circle to get the circumference. For instance, if the radius is 14 centimeters, the circumference is 88 centimeters.
Divide the arc measure by 360 degrees, and then multiply the answer by the circumference of the circle. For instance, if the arc measure is 90 degrees, and the circumference of the circle is 88 centimeters, divide 90 degrees by 360 degrees to get 1/4, then multiply the value by 88 centimeters to get 22 centimeters. This is the length of the arc.