supplementary angles need to equal 180 degrees
one angle = t
the other angle = 4 x t or 4t
so we now have t + 4t = 180
4 + 4t = 5t
so we have 5t = 180
divide both sides by 5:
t = 180 /5
t = 36
so angle t = 36 degrees
the other angle = 4 x 36 = 144 degrees