a unit circle has a radius of 1 unit. explain why one complete rotaion around a unit circle is a distance of 2pi

Question

trigonometric funtions

Answer 1

The circumference, C, of a circle is:

 

C = 2*pi*radius

 

When radius = 1, C = 2*pi*1 = 2pi.  One complete rotation takes you once around the circumference.