What would be the arc length of 1/5 of a circle with a radius of 4 ft?

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.

The complement of an angle is one-sixth the measure of the supplement of the angle. what is the measure of the complement angle?

Vertical angles must check all that apply