Answer:
This is done by stating descriptions of these terms.
Explanation:
Undefinable terms are terms with no formal definitions. Formal definitions are obtained when specific words are used to define a term. In mathematics, specifically, Geometry words like line, point, and plane have no definite definition, So descriptions are used to identify them.
For example, in describing a point, we note that a point has no dimensions, it is usually denoted with a capital letter, and it indicates a position. Also in a coordinate plane, it is denoted with descriptions such as (u,v). Corresponding descriptions are given of other undefinable terms.