Question

Find the area of ΔABC whose vertices are A(1, 2) B(–2, 3) and C(–3, –4).

Answer 1

  A (1,2) B (-2,3) and C (-3,-4)  are the vertices of . ΔABC Then,

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

Area of triangle ABC

`=1/2 {x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)}`

` = 1/2 { 1(3-(-4))+(-2)(-4-2) + (-3)(2-3)}`

`=1/2 { 1(3+4)-2(-6) -3 (-1)}`

`=1/2 {7+12+3}`

`=1/2 (22)`

= 11 sq. units