143,981 views
19 votes
19 votes
What is the area of a triangle whose vertices are J(-2, 1), K(0, 3), and L(3,-4)?

Enter your answer in the box.
units²

User Kiandra
by
2.7k points

1 Answer

19 votes
19 votes

Answer: 10 units²

Explanation:

To find the area of a triangle when given its vertices, we can use this formula:


\displaystyle (Jx(Ky - Ly) + Kx(Ly - Jy) + Lx(Jy - Ky) )/(2)

We will plug in our coordinate points and solve. The area will be the absolute value simplification of this expression.

J(-2, 1) is (Jx, Jy), K(0, 3) is (Kx, Ky), and L(3,-4) is (Lx, Ly).


\displaystyle (Jx(Ky - Ly) + Kx(Ly - Jy) + Lx(Jy - Ky) )/(2)


\displaystyle (-2(3 - -4) + 0(-4 - 1) + 3(1 - 3) )/(2)


\displaystyle (-14+ 0-6)/(2)


\displaystyle (-20)/(2)


\displaystyle -10,\;\;|-10|=10

User ScottWest
by
2.3k points