[tex]\large\boxed{\begin{array}{l}\underline{\rm \acute Area\,do\,tr\hat angulo\,ret\hat angulo}\\\sf A=\dfrac{cateto\,maior\cdot cateto\,menor}{2}\\\\\sf A=\dfrac{5\cdot8}{2}=\dfrac{40}{2}=20\,m^2\end{array}}[/tex]
