Pi r² is circle's area expression.
So the r is radius,.
Answer:
This is done by stating descriptions of these terms.
Step-by-step 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.
Based from the graph, I think the answer is D. a piece-wise function with separate pieces of linear and step-functions. This is because as you can see from the graph, for intervals [0,1], [5,6], and [10,11] the function is linear. On the other hand, for the remaining intervals, it has a constant value which can be described as a step function.