Triangle ABC, with vertices A(5,-9), B(7,-3), and C(2,-4), is drawn inside a
rectangle, as shown below.

Answer:
Find the area of the reactangle: Area = 5 * 6
Then find the area of the three right triangles
(1 * 5) / 2 = Area of top-side triangle
(3 * 5) / 2 = Area of left-side triangle
(2 * 6) / 2 = Area of right-side triangle
Now add all areas of all the triangles and subtract it from the rectangle.
This is the area inside the triangle
Step-by-step explanation: