O' is the centre of an equilateral triangle ABC F_(1),F_(2) and F_(3) are three force acting along the sides AB, BC and AC as shown in figure. What should be the magnitude of F_(3),so that the total torque about 'O' is zero ?

O' is the centre of an equilateral triangle ABC F_(1),F_(2) and F_(3)

1.	O' is the centre of an equilateral triangle ABC F_(1),F_(2) and F_(3) are three force acting along the sides AB, BC and AC as shown in figure. What should be the magnitude of F_(3),so that the total torque about 'O' is zero ?
Answer» `(F_(1)+F_(2))/(2)` `2(F_(1)+F_(2))` `(F_(1)+F_(2))` `(F_(1)-F_(2))` ANSWER :C