Sire, there is no royal road to geometry.
A line is length without breadth.
A prime number is one (which is) measured by a unit alone.
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.
The laws of nature are but the mathematical thoughts of God.
If produced indefinitely, meet on that side on which the angles are less than two right angles.
Better balance, less pain and less restless leg syndrome.
Give him threepence, since he must make a gain out of what he learns.
And the whole is greater than the part.
Things which are equal to the same thing are also equal to one another.
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.