In $\triangle{ABC}$, $\cos{B}=\frac{3}{5}$ and angle A is 90 degrees. What is $\cos{C}$?
cos c = 4/5
cos c = sin b
find sin b cos^2 + sin^2 = 1
9/25 + sin^2 =1
sin^2 = 16/25
sin b = 4/5 cos c = sin b = 4/5
+501 
+37146 
