Rigid motions are, exclusively, rotations, reflections, and translations. If you can move one polygon onto the other by using only those motions, they are congruent. One pentagon can, for example, be translated onto another pentagon, making them congruent. If, after being translated, point A is on point F and B on G and C on H and D on I and E on J, the congruence statement is: [tex] ABCDE\cong FGHIJ.[/tex]
