What is the reference angle of -370 degrees or (8pi)/3?

##-370^o -= -10^o##
This angle is ##10^o## away from the x-axis
Therefore the reference angle is ##10^o##
##(8pi)/3 -=(2pi + (2pi)/3)##
##-= (pi – pi/3)##
This angle is ##pi/3## away from the (negative) x-axis
Therefore the reference angle is ##pi/3##