This key facts covers Types of Triangles within Properties of Triangles for GCSE Mathematics. Revise Properties of Triangles in Geometry & Measures for GCSE Mathematics with 12 exam-style questions and 3 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 2 of 9 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Types of Triangles
| Type | Sides | Angles | Key Feature |
|---|---|---|---|
| Equilateral | All 3 equal | All 60° | 3 lines of symmetry, rotational order 3 |
| Isosceles | 2 equal | 2 equal (base angles) | 1 line of symmetry |
| Scalene | All different | All different | No symmetry |
| Right-angled | Any combination | One 90° angle | Other two angles add to 90° |
Practice questions for Properties of Triangles
What is the sum of the interior angles of any triangle?
Describe the key properties of an equilateral triangle. State two properties relating to sides and two relating to angles.
Quick recall flashcards
Isosceles Triangle
Two equal sides, two equal angles
Triangle Angle Sum
Always 180°