Look at ∠A, the angle which resides on (1, 3). If we count 5 units down, you find the other endpoint on side AC. Hence, the length of side AC is 5 units. This figure is equal to the height of the graphed triangle.
If we mirror this process with the figure representing the triangle's length, side BC, we get 4 units.
The formula for calculating a triangle's area is [tex]\frac{1}{2}bh[/tex]. In this context, the base of the triangle is the same as the length. Now, let's plug in the base and the height.
[tex]\frac{1}{2}(4)[/tex] × [tex](5) = 10[/tex]
The area of triangle ABC is 10 squared units.
