Question

5)calcule a área do triângulo, sendo dados os vértices :A(2,4),B(-6,2)ec(0,-2).​

Answer 1

$\Large\boxed{\begin{array}{l}\sf M=\begin{vmatrix}\sf2&\sf4&\sf1\\\sf-6&\sf2&\sf1\\\sf0&\sf-2&\sf1\end{vmatrix}\\\sf det~M=2\cdot(2+2)-4\cdot(-6)+1\cdot(12)\\\sf det~M=8+24+12\\\sf det~M=44\\\sf A=\dfrac{|det~M|}{2}\\\\\sf A=\dfrac{44}{2}\\\\\sf A=22~ u\cdot a\end{array}}$