It follows at once from the last proposition that the centre of gravity of any triangle is at the intersection of the lines drawn from any two angles to the middle points of the opposite sides respectively.


Book 1, Proposition 14. - On the Equilibrium of Planes


It follows at once from the last proposition that the centre of gravity of any triangle is at the intersection of the lines drawn from any two angles ...

It follows at once from the last proposition that the centre of gravity of any triangle is at the intersection of the lines drawn from any two angles ...

It follows at once from the last proposition that the centre of gravity of any triangle is at the intersection of the lines drawn from any two angles ...

It follows at once from the last proposition that the centre of gravity of any triangle is at the intersection of the lines drawn from any two angles ...