If the vertices of a triangle are (1,2),(4,−6)  and  (3,5),  then its area is

Area of the triangle whose vertices are given Δ=12[x1(y2−y3)+x2(y3−y1)+x3(y1−y2)] Δ=12[1(−6−5)+4(5−2)+3(2+6)] Δ=252  sq. units.