<P> In geometry, "Corresponding parts of congruent triangles are congruent" (CPCTC) is a succinct statement of a theorem regarding congruent trigonometry, defined as triangles either of which is an isometry of the other . CPCTC states that if two or more triangles are congruent, then all of their corresponding angles and sides are congruent as well . CPCTC is useful in proving various theorems about triangles and other polygons . </P> <P> If triangles ABC and DEF are congruent, denoted as </P> <Dl> <Dd> △ A B C ≅ △ D E F, (\ displaystyle \ triangle ABC \ cong \ triangle DEF,) </Dd> </Dl>

If dec bec which is true by cpctc