Give him threepence, since he must make a gain out of what he learns.
In right-angled triangles the square on the side subtending the right angle is equal to the squares on the sides containing the right angle.
Sire, there is no royal road to geometry.
That, if a straight line falling on two straight lines makes the interior angles on the same side less than two right angles, the two straight lines, if produced indefinitely, meet on that side on which the angles are less than two right angles.
And the whole is greater than the part.
The laws of nature are but the mathematical thoughts of God.
A prime number is one (which is) measured by a unit alone.
A line is length without breadth.