ABC is an equilateral with O as its centre `vecF_(1), vecF_(2)` and `vecF_(3)` represent three forces acting along the sides AB, BC and AC respectively. If the total torque about O is zero then the magnitude of `vecF_(3)` is :

Options

A. `F_(1)+F_(2)`
B. `F_(1)-F_(2)`
C. `(F_(1)+F_(2))/(2)`
D. `2(F_(1)+F_(2))`

Answer

A

Explanation

For rotational equilibrium -
`F_(1)x+F_(2)x=F_(3)ximpliesF_(3)=F_(1)+F_(2)`