2D Shapes
Year 7 📐 Geometry & Measures Properties of triangles, quadrilaterals and polygons.
🔷 Properties of 2D Shapes
Polygons are flat shapes with straight sides. Their properties include side lengths, angles, and lines of symmetry.
| Shape | Sides | Interior angle sum | Lines of symmetry |
|---|---|---|---|
| Triangle | 3 | 180° | 0–3 |
| Quadrilateral | 4 | 360° | 0–4 |
| Pentagon | 5 | 540° | 0–5 |
| Hexagon | 6 | 720° | 0–6 |
📐 Triangle Types
Triangles are classified by their sides or their angles.
- Equilateral: 3 equal sides, 3 equal angles (60° each)
- Isosceles: 2 equal sides, 2 equal base angles
- Scalene: No equal sides or angles
- Right-angled: One angle = 90°
⚡ Angle Sum
$$\text{Angles in a triangle} = 180°$$🔶 Quadrilateral Properties
Quadrilaterals are four-sided polygons with specific properties to memorise.
| Shape | Key Properties |
|---|---|
| Square | 4 equal sides, 4 right angles |
| Rectangle | Opposite sides equal, 4 right angles |
| Parallelogram | Opposite sides parallel and equal |
| Rhombus | 4 equal sides, opposite angles equal |
| Trapezium | One pair of parallel sides |
| Kite | Two pairs of adjacent equal sides |
Ready to test yourself? Click the Quiz tab above to answer questions on this topic!
Interactive Demonstration — 2D Shapes
🔷 Shape Properties Tool