Find the Reference Angle -16pi

$- 16 π$

Step 1

Find an angle that is positive, less than $2 π$ , and coterminal with $- 16 π$ .

Add $2 π$ to $- 16 π$ until the angle falls between $0$ and $2 π$ . In this case, $2 π$ needs to be added $9$ times.

$- 16 π + 9 (2 π)$

Simplify.

Multiply $2$ by $9$ .

$- 16 π + 18 π$

Add $- 16 π$ and $18 π$ .

$2 π$

Step 2

Since the angle $2 π$ is in the fourth quadrant, subtract $2 π$ from $2 π$ .

$2 π - 2 π$

Step 3

Subtract $2 π$ from $2 π$ .

$0$