Question Number 89741 by cindiaulia last updated on 19/Apr/20
Commented by jagoll last updated on 19/Apr/20
$$\mathrm{area}\:=\:\frac{\mathrm{1}}{\mathrm{2}}\:\mid\begin{vmatrix}{\mathrm{0}\:\:\:\:\:\mathrm{0}}\\{\mathrm{1}\:\:\:\:\:\mathrm{1}}\end{vmatrix}+\:\begin{vmatrix}{\mathrm{1}\:\:\:\:\:\:\mathrm{1}}\\{\frac{\mathrm{2}}{\mathrm{5}}\:\:\frac{\mathrm{8}}{\mathrm{5}}}\end{vmatrix}+\:\begin{vmatrix}{\frac{\mathrm{2}}{\mathrm{5}}\:\:\:\:\frac{\mathrm{8}}{\mathrm{5}}}\\{\mathrm{0}\:\:\:\:\:\:\:\mathrm{0}}\end{vmatrix}\mid \\ $$$$=\:\frac{\mathrm{1}}{\mathrm{2}}\:\mid\:\mathrm{0}+\frac{\mathrm{6}}{\mathrm{5}}+\mathrm{0}\:\mid\:=\:\frac{\mathrm{3}}{\mathrm{5}} \\ $$