As per the principle of moments,“The sum of the clockwise moments about any point must be equal to the sum of anti-clockwise moments about the same point, provided that the body is in equilibrium under the action of a number of parallel forces.”
According to the principle of moments,
Sum of anti-clockwise moments = sum of clockwise moments
The formula or equation for Principle of moments is given as,
m1d1 + m2d2 =m3d3 + m4d4