Question 158181
{{{A=(1/2)h(B+b)}}} Start with the given equation.



{{{80=(1/2)h(12+8)}}} Plug in A=80, B=12, and b=8



{{{80=(1/2)h(20)}}} Add



{{{80=h(1/2)(20)}}} Rearrange the terms.



{{{80=h(20/2)}}} Multiply 



{{{80=h(10)}}} Reduce



{{{80/10=h}}} Divide both sides by 20 to isolate h.



{{{8=h}}} Reduce



So the answer is {{{h=8}}} which means that the height is 8 units.




Check:


{{{A=(1/2)h(B+b)}}} Start with the given equation.



{{{80=(1/2)(8)(12+8)}}} Plug in A=80, h=8, B=12, and b=8



{{{80=(1/2)(8)(20)}}} Add



{{{80=160/2}}} Multiply



{{{80=80}}} Reduce. Since the equation is true, this means that we've verified the solution.