Step 1: Locate the coordinates of the endpoints.

            EXAMPLE: The given points M (2, 3) and N (-1, 0), (2, -4.)

            Therefore, (x_1, y_1) = (2, 3),(x_2, y_2) = (-1, 0) and (x_3, y_3) = (2, -4).

Step 2: Set up triangle area formula when vertices are given.

            FORMULA: Area of the triangle

             \frac{1}{2} {x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2)}

Step 3: Plug the corresponding coordinates into the Area of triangle formula.

              EXAMPLE: \frac{1}{2} {x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2)}

                                 \frac{1}{2} (2*[0 -(- 4)] + (-1)*[-4 – 3] + 2*[3 – 0])

Step 3: Simplify further

           NOTE: Apply the BODMAS rules

           EXAMPLE:   \frac{1}{2} (2*[0 -(- 4)] + (-1)*[-4 – 3] + 2*[3 – 0])

                                \frac{1}{2} (2*[4] + (-1)*[-7] + 2*[3])

                                 \frac{1}{2} (8 + 7 + 6])

                                 \frac{1}{2} (21)