Let AD be the altitude and BC the base
tan B = AD / BD = 3/5 = 3 / 5
tan C = AD / CD = 1/4 = 3 / 12
BD = 5 / (12 + 5) *32 = (5/17) * 32 = 160 / 17
AD / BD = AD / (160/17) = 3/5
AD = (160 / 17) *( 3 / 5) = 96 / 17
[ABC] = (1/2) BC * AD = (1/2) 32 * 96 / 17 = 1536 / 17

