Home > PC3 > Chapter 10 > Lesson 10.2.2 > Problem10-138

10-138.

Calculate the area of a triangle with vertices at $(−3, 7), (13, −10)$, and $(−5, 1)$.

Let $(a, b), (c, d)$, and $(e, f)$ be the vertices of a triangle. Then:
$A= \pm \frac{1}{2}\left| \begin{array} { c c c } { a}&{b}&{1} \\ { c}&{d}&{1} \\ { e}&{f}&{1} \end{array} \right|$
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