Vertices of triangle in complex form is z,iz,z+iz In cartesian form vertices are (x,y),(−y,x) and (x−y,x+y) ∴ Area of triangle =21x−yx−yyxx+y111=21[x(x−x−y)−y(−y−x+y)+1(−yx−y2−x2+xy)] =21[−xy+xy−y2−x2]=21(x2+y2)(∵ Area can not be negative )=21∣z∣2(∵z=x+iy,∣z∣2=x2+y2)