congruent

Everyday

1. (maths) Exactly the same shape and size; one shape fits exactly on top of the other, even if turned or flipped. tree →
2. (formal) In agreement or matching (congruent with the facts). tree →
3. (maths) In number work, having the same remainder when divided by a number. tree →

In the lessons

In geometry lessons: congruent triangles, congruent shapes; tests such as SSS, SAS, ASA. Similar shapes have the same shape but can be different sizes; congruent shapes are also the same size.

Examples

• These two triangles are congruent. tree →
• Congruent shapes have equal sides and angles. tree →
• Cut out two congruent squares. tree →
• A shape and its mirror image are congruent. tree →
• The two halves of a butterfly are congruent. tree →
• Her actions were congruent with her words. tree →

Note

Congruent is not the same as similar: similar = same shape, congruent = same shape and same size. Turning or flipping a shape keeps it congruent; enlarging does not. Symbol: ≅.