Respuesta :

a whole circle is 2π. an angle + or - the multiples of 2π, that is, rotated a full circle counterclockwise or clockwise, will get a co-terminal angle
in this case, it can be (8/4)π+(5/4)π=(13/4)π, (16/4)π+(5/4)π=(21/4)π. or 
(5/4)π-(8/4)π=(-3/4)π