Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.

Rise above oneself and grasp the world.

The centre of gravity of any cylinder is the point of bisection of the axis.

Those who claim to discover everything but produce no proofs of the same may be confuted as having actually pretended to discover the impossible.

How many theorems in geometry which have seemed at first impracticable are in time successfully worked out!

Give me but a firm spot on which to stand, and I shall move the earth.

The perimeter of the earth is about 3,000,000 stadia and not greater.

The centre of gravity of any parallelogram lies on the straight line joining the middle points of opposite sides.

Man has always learned from the past. After all, you can't learn history in reverse!

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.