[tex]\bf \textit{area of a trapezoid}\\\\
A=\cfrac{h(a+b)}{2}\quad
\begin{cases}
a,b=\stackrel{parallel~sides}{bases}\\
h=height\\
--------\\
A=150\\
a+b=14
\end{cases}\implies 150=\cfrac{h(14)}{2}
\\\\\\
300=14h\implies \cfrac{300}{14}=h\implies \cfrac{150}{7}=h\implies 21\frac{3}{7}=h[/tex]
