Question

What is the difference between a defined and an undefined term in Geometry?

Answer 1

a point, a line and a plane are all undefined terms, because we don't know their exact size.

Answer 2

When you look at a triangle however, it's defined, although it's components can be undefined.

Answer 3

In Geometry, the terms point, line, and plane are accepted as intuitive ideas and are not defined. These undefined terms are then used in the definition of other terms. Example: Space is defined to be the set of all point.s