Question

find the area of the triangle whose vertices are (-2,1) (3,1) (2,-3)? ​

Answer 1

Area =1/2 [x1(y2 – y3) + x2(y3 – y1) + x3(y1 – y3)]

=1/2{-2(1-(-3)) + 3(-3-(-2)) + 2(-2-(-3)}  (absolute value-in the end sign does not matter)

= 1/2 {-8 -3+2}

=9/2=4.5