If F→ is the force acting on a particle having position vector r→ and τ→ be the torque of this force about the origin, then

Torque is an axial vector, i.e., its direction is always perpendicular to the plane containing vectors r→ and F→.τ→ = r→ ×F→Torque is perpendicular to both r→ and F→τ→.r→ = 0F→.τ→ = 0