Become a math whiz with AI Tutoring, Practice Questions & more.

Join for Free
HotmathMath Homework. Do It Faster, Learn It Better.

Radian Measure of an Angle

The measure of an angle is determined by the amount of rotation from the initial side to the terminal side.  One way to measure angles is in radians.  To define a radian , use a central angle of a circle (an angle whose vertex is the center of the circle).  One radian is the measure of a central angle that intercepts an arc s equal in length to the radius r of the circle.

Math diagram

Since the circumference of a circle is 2 π r , one revolution around a circle of radius r corresponds to an angle of 2 π radians because s r = 2 π r r = 2 π radians .

Subjects Near Me
Popular Cities
Popular Subjects
;
Download our free learning tools apps and test prep books
varsity tutors app storevarsity tutors google play storevarsity tutors amazon storevarsity tutors ibooks store