<Li> Two line segments are congruent if they have the same length . </Li> <Li> Two angles are congruent if they have the same measure . </Li> <Li> Two circles are congruent if they have the same diameter . </Li> <P> In this sense, two plane figures are congruent implies that their corresponding characteristics are "congruent" or "equal" including not just their corresponding sides and angles, but also their corresponding diagonals, perimeters and areas . </P>

When do we say that two circles are congruent