Question

A=1/2 h (b+c) solve for b

Answer 1

`a = (1)/(2) h(b + c) \\ (2a)/(h) = b + c \\ (2a)/(h) - c = b \\ thank \: you`

Answer 2

Hi ;-)

`A=(1)/(2)h(b+c) \ \ /\cdot2\\\\h(b+c)=2A \ \ /:h; \ h\\eq0\\\\b+c=(2A)/(h) \ \ /-c\\\\\boxed{b=(2A)/(h)-c}`