Two triangles are similar if they have exactly the same shape. They may have different sizes though.

Summary/Background
If two shapes are similar then one is an enlargement of the other.
Software/Applets used on this page
Glossary
union
The union of two sets A and B is the set containing all the elements of A and B.
This question appears in the following syllabi:
Syllabus | Module | Section | Topic | Exam Year |
---|---|---|---|---|
AQA GCSE (9-1) Foundation (UK) | G: Mensuration and Calculation | G19: Applying Congruence and Similarity | Similarity | - |
CBSE IX (India) | Geometry | Triangles | Congruence and similarity | - |
CBSE X (India) | Geometry | Triangles | Similar triangles | - |
CIE IGCSE (9-1) Maths (0626 UK) | 3 Geometry | B3.4 Similar Figures | Similarity | - |
Edexcel GCSE (9-1) Foundation (UK) | G: Mensuration and Calculation | G19: Applying Congruence and Similarity | Similarity | - |
GCSE Higher (UK) | Geometry | Properties of shapes | Similarity | - |
OCR GCSE (9-1) Foundation (UK) | 9: Congruence and Similarity | 9.04c: Similar Shapes | More Lengths in Enlargements | - |
Universal (all site questions) | P | Properties of shapes | Similarity | - |