Question

How can i prove that... ( Trigonometry )

Answer 1

Not sure, but perhaps the law of sines/cosines will help?

Answer 2

(just a guess!)

Answer 3

The only hint i got was:
notice that sin(A+B) = Sin(180-(A+B)) = Sin(C)

Answer 4

I don't see how they use the C.
I get that h = Sin A * b = Sin B * a

Answer 5

Yes i solved it.
h = Sin A * b
b = c/Sin(C) * Sin B = c / Sin(A +B) * Sin B
h = Sin A * c * Sin B / Sin(A + B)

Answer 6

Nice work.