My name is holly i am a tenth grader at bonita vista high school in san diego california. This is a secondary question. I am a student. What is the formoula for finding the arc length of a central angle of a circle?? Hi Holly, If you consider a circle with radius r then its circumference is . Thus when the angle is 360^{o} the arclength is
Arclength = If the angle is less than 360^{o}, that is some fraction of 360^{o}, then the arclength is the same fraction of Arclength = If you measure the angle in radians rather than degrees then the expression is simpler. Since 360^{o} is radians, the arclength in the second diagram is .
Cheers,
