Respuesta :

Check the picture below.

[tex]\textit{area of a trapezoid}\\\\ A=\cfrac{h(a+b)}{2}~~ \begin{cases} h=height\\ a,b=\stackrel{parallel~sides}{bases}\\[-0.5em] \hrulefill\\ h=2\\ a=3\\ b=9 \end{cases}\implies A=\cfrac{2(3+9)}{2}\implies A=12[/tex]

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