In this exercise we will practice defining terms. Be careful to use only previously defined terms, and take care not to use imprecise and colloquial language in your definitions.
(a) Define the term midpoint of a segment.
(b) Define the term perpendicular bisector of a segment.
(c) Define the tem triangle defined by three non-collinear points $A, B, C$.
(d) Define the term equilateral triangle.
In the next set of exercises, we consider the logical equivalence of Euclid's fifth postulate with Playfair's Postulate. You may use any of the first 28 Propositions of Euclid (found in Appendix B) and/or any of the results from this section for these exercises.