y=ax−bc.......(i)y=bx−ca......(ii)y=cx−ab.......(iii)
solving (i) and (ii)
⇒x=−c,y=−c(a+b)
So the coordinates of A are (−c,−c(a+b))
solving (ii) and (iii)
⇒x=−a,y=−a(b+c)
So the coordinates of B are (−a,−a(b+c))
Solving (i) and (iii)
⇒x=−b,y=−b(a+c)
So the coordinates of C are (−b,−b(a+c))
Area of triangle =12|x1(y2−y3)+x2(y3−y1)+x3(y1−y2)|
Δ=12|−c(−ab−ac+ab+bc)−a(−ab−bc+ac+bc)−b(−ac−bc+ab+ac)|Δ=12|−c(bc−ac)−a(ac−ab)−b(ab−bc)|Δ=12(ac2−bc2+ba2−ca2+cb2−ab2)Δ=12(a−b)(b−c)(c−a)