Definition of Congruence and Some Basic Properties

Students know the definition of congruence and related notation. Students know that to prove two figures are congruent, there must be a sequence of rigid motions that maps one figure onto the other. Students know that the basic properties of congruence are similar to the properties for all three rigid motions (translations, rotations, and reflections). A geometric figure is said to be congruent to another geometric figure if there is a sequence of rigid motions that maps them.