"Two forces [tex]F_1[/tex] and [tex]F_2[/tex] act along the two sides of an equilateral triangle as shown...Point O is the intersection of the altitudes of the triangle. Find a third force [tex]F_3[/tex] to be applied at B and along BC that will make the total torque zero about the point O." So the sum of the torques = 0. I don't know what to do first. Should I put the forces into component form and take the tangential component of the forces??