Line of gravity :
The line of gravity can be represented by drawing a straight line from the centre of gravity to the ground.
An object is most stable when the fine of gravity falls through the centre of the base of support. This is because it increases the distance that the centre of gravity can be moved before balance is compromised. Moving the line of gravity towards the edge of the bas of support reduces a body's stability. The further off-centre from the base of support the centre of gravity is the less stable the body.