Euclid’s Definitions

Euclid’s Definitions

Euclid listed some definitions.

Some of them are

1. A point is that which has no part.
2. A line is breadthless length.
3. The ends of a line are points.
4. A straight line is a line which lies evenly with the points on itself.
5. A surface is that which has length and breadth only.
6. The edges of a surface are lines.
7. A plane surface is a surface which lies evenly with the straight lines on itself.
   
   

We observe that in the definitions,

some things need to be explained further.

Like

• In Definition 2 -  “A line is breadthless length.” , what is a length? What is breadthless?

In this question , we try to define some terms like parallel lines, radius of circle, square etc.