You can put this solution on YOUR website! First a definition - reference angles are the number of degrees to get back to the x-axis at 180 or 360 degrees.
a)32 degrees
reference angle = 32 degrees
--
b)112 degrees
reference angle = 78 degrees
--
c)230 degrees
reference angle = 40 degrees
--
d)350 degree
reference angle = 10 degrees