Question

calcule a area do triangulo, cujos vertices sao:A (1,2), B (3,6) e C (7,5)

Answer 1

$Ola' \\ \\ A= \frac{D_{et}}{2} \\ \\ A= \frac{\begin{vmatrix}1&2&1 \\ 3&6&1 \\ 7&5&1\end{vmatrix}}{2} \\ \\ A= \frac{\bigg|(6+14+15)-(42+5+6)~\bigg|}{2} \\ \\ A= \frac{|-18 ~|}{2} \\ \\\boxed{\boxed{ A=9u\²}}~~--\ \textgreater \ \acute{a}rea~do~tri\^angulo$

$\mathbb{iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii}\\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Espero~ter~ajudado!!$