The points, `z_1,z_2,z_3,z_4,` in the complex plane are the vartices of a parallelogram taken in order, if and only if (a)`z_1+z_4=z_2+z_3` (b)`z_1+z_3=z_2+z_4` (c)`z_1+z_2=z_3+z_4` (d) None of these

The points z_1, z_2, z_3, z_4 in the complex plane form the vertices of a parallelogram iff :

The point z_(1),z_(2),z_(3),z_(4) in the complex plane are the vertices of a parallogram taken in order, if and only if. (1) z _(1) +z_(4)=z_(2)+z_(3) (2) z_(1)+z_(3) =z_(2) +z_(4) (3) z_(1)+z_(2) =z_(3)+z_(4) (4) z_(1) + z_(3) ne z_(2) +z_(4)

Find the relation if z_(1),z_(2),z_(3),z_(4) are the affixes of the vertices of a parallelogram taken in order.

If z_1,z_2,z_3,z_4 be the vertices of a parallelogram taken in anticlockwise direction and |z_1-z_2|=|z_1-z_4|, then sum_(r=1)^4(-1)^r z_r=0 (b) z_1+z_2-z_3-z_4=0 a r g(z_4-z_2)/(z_3-z_1)=pi/2 (d) None of these