Lami’s theorem states that if the three coplanar concurrent forces acting on a body keep it in equilibrium, then:
1
Each force is proportional to the cosine of the angle between the other two forces.
2
Each force is proportional to the cotangent of the angle between the other two forces.
3
Each force is proportional to the tangent of the angle between the other two forces.
4
Each force is proportional to the sine of the angle between the other two forces.