This is the same as the degrees version but in the degrees case the 2p360 converts the degrees to radians. You know that th 120 since it is given that angle KPL equals 120 degrees. From this point on we are going to use the following formula for the length of the curve.
S rth when th is measured in radians.
The 1 part of the Arc Length Formula guarantees we get at least the distance between x values such as this case where f x is zero. So the arc length between 2 and 3 is 1. A r 2 th2 when th is measured in radians and. S a b 1 d y d x 2 d x.