pre calcalus
posted by gion on .
a circle with 4 inch radius, find length of arc when intercepted by central angle of 240 degrees

r=radius
θ=central angle in radians
To convert degrees to radians, multiply the number of degrees by π and divide by 180°.
Arc length, l = rθ
Example:
θ = 90°
=90*π/180=π/2
r = 10 m
Length of arc
= rθ
= 10 * π/2
= 5π
= 15.7 m 
a circle has a radius of 4cm. Find the length of an arc subtended by a central angle of 150 degrees.