A right triangle has hypotenuse 5 inches long. Its area is 4 square inches. How long are the other sides?

Answer 1

1/2 bh=4
bh=8

b^2+h^2=25
h^2/64 +h^2=25
65h^2=25*64
h= 5*8/sqrt65

Answer 2

I don't quite follow the last three lines. Could you please explain?