CPCTC

``CPCTC'' is an acronym which stands for ``corresponding parts of congruent triangles are congruent.'' In other words, if

(1)

• $\angle A \cong \angle D$ ;
• $\overline{AB} \cong \overline{DE}$ ;
• $\angle B \cong \angle E$ ;
• $\overline{BC} \cong \overline{EF}$ ;
• $\angle C \cong \angle F$ ;
• $\overline{AC} \cong \overline{DF}$ .

Note. The notation in (1) indicates that the isomorphism in question maps $A\mapsto D$ , $B\mapsto E$ , and $C\mapsto F$ .