The area of a triangle whose vertices are given by coordinates (1, 2),(–4, –3) and (4, 1) will be :

We can find the area of a triangle can be found as:

$\Rightarrow \text{ Area of triangle }=\frac{1}{2}\left[x_1\left(y_2-y_3\right)+x_2\left(y_3-y_1\right)+x_3\left(y_1-y_2\right)\right]$

$\Rightarrow \mathrm{Area} \mathrm{of} \mathrm{triangle}=\frac{1}{2}\times \left[1\right(-3-1)+(-4\left)\right(1-2)+4(2-(-3)]$

$\Rightarrow \frac{20}{2}=10\text{ sq. units }$