What is the reference angle in degrees for 31π 6?

Okay - so 12pi/6 = 360. We need to make 31pi/6 between 0pi/6 and 12pi/6 in order to obtain the reference angle. So let's do that.

31pi/6 - 12pi/6 = 19pi/6

19pi/6 - 12pi/6 = 7pi/6

The reference angle in radians is 7pi/6, but it wants degrees - so we convert to degrees using 180/pi.

7pi/6 * 180/pi = 210 degrees