Answer:
Sin 73 = 0.956304756, Cos 17 = 0.956304756
Sin 18 = 0.3090169944, Cos 72 = 0.3090169944
This only works when the Sin angle and the Cos angle are complementary, meaning they add up to 90 degrees.
55+35=90
30+60=90
15+75=90
73+17=90
18+72=90
(Keep in mind the values for the Sin and Cos are approximations)
I hope this helped! :D