One reason is that the center of gravity of an object always orients itself with minimum potential energy on a vertical line below the support point.

Try understanding this: Remember that the object is in equilibrium when it hangs below its suspension point and an object is in equilibrium if it is supported at its center of gravity, at a point directly above its center of gravity or at a point directly below its center of gravity. That is why the intersection of the three lines on an irregular shaped lamina is the Center Of Gravity.

Try understanding this: Remember that the object is in equilibrium when it hangs below its suspension point and an object is in equilibrium if it is supported at its center of gravity, at a point directly above its center of gravity or at a point directly below its center of gravity. That is why the intersection of the three lines on an irregular shaped lamina is the Center Of Gravity.