Question

I need help :( I forgot how to do this

Answer 1

Answer:

$A=\frac{1}{2}h(b_{1}+b_{2} ) | *2\\2A=h(b_{1}+b_{2} ) | : (b_{1}+b_{2} )\\\frac{2A}{(b_{1}+b_{2} )} = h$

I hope it's good.

Take care !