StudyDeck

Congruence

Exam code: 4024
Written by: Ashika|Reviewed by: Caroline Carroll|Updated 2 July 2026

Congruence

Congruence

What is congruence?

  • Two shapes are congruent if they are identical in shape and size

    • One may be a reflection, rotation, or translation of the other

  • If one shape is an enlargement of the other, then they are not identical in size and so are not congruent

    • If all the angles are the same, then the shapes are similar

How do we prove that two shapes are congruent?

  • To show that two shapes are congruent you need to show that they are both the same shape and the same size

    • If a shape has been reflected, rotated or translated, then its image is congruent to it

  • Show that corresponding sides are the same length

  • Show that corresponding angles are the same size

  • You do not need to show that they are facing in the same direction