MathsYears 10–11Geometry - Properties of Shapes

Congruence and similarity

Prove congruence using SSS/SAS/ASA/RHS; use similarity to find missing lengths and areas

What you'll learn

  1. 1

    Imagine two identical puzzle pieces that fit perfectly together — they are the same shape and the same size.

  2. 2

    If two shapes are congruent, what must be true about them?

  3. 3

    Here are two triangles. One is a copy of the other — they are congruent. The third triangle is a zoomed-in version — it is similar.

  4. 4

    Are these two rectangles congruent?

  5. 5

    Drag the second triangle to see if it matches the first exactly — that's congruence.

  6. 6

    Two shapes are similar. Their angles are the same, but one side is twice as long. Are they similar or congruent?

  7. 7

    Triangle A has sides 3 cm, 4 cm, 5 cm. Triangle B has sides 6 cm, 8 cm, 10 cm. Are they similar?

Practise Congruence and similarity with Whizlo

Free AI-tutored lessons, unlimited practice questions, and progress tracking for ages 14–16. Aligned to the UK National Curriculum.