Cambridge questions are written in precise mathematical English. If you know exactly what product, difference, justify and estimate ask you to do, you will not lose marks answering the wrong question.
| Term | What it means | Example |
|---|---|---|
| polygon | A closed shape made of straight sides. | A hexagon has 6. |
| regular polygon | All sides equal and all angles equal. | A square. |
| vertex | A corner where sides or edges meet. | A cube has 8. |
| interior angle | An angle inside a polygon at a vertex. | 108° in a regular pentagon. |
| exterior angle | The angle between a side and the next side extended. | They total 360°. |
| centre | The exact middle of a circle. | Every radius starts there. |
| radius | The distance from the centre to the edge. | Half the diameter. |
| diameter | The distance right across through the centre. | Twice the radius. |
| circumference | The distance all the way round a circle. | Its perimeter. |
| chord | A straight line joining two points on a circle. | A diameter is the longest. |
| line of symmetry | A line a shape folds along so the halves match. | A rectangle has 2. |
| rotational symmetry | Looking the same after a turn about a point. | A square has order 4. |
| order of rotational symmetry | How many times a shape looks the same in a full turn. | A parallelogram has order 2. |
| face | A flat surface of a solid. | A cube has 6. |
| edge | A line where two faces meet. | A cube has 12. |
| net | A flat shape that folds into a solid. | A cube has 11 nets. |
| prism | A solid with the same cross-section throughout. | A tent. |
| pyramid | A solid rising from a base to a single apex. | The Great Pyramid. |