For a circle with radius r, the area = \pi r^2 and perimeter = 2 \pi r.

On a calculator \pi \times 4.27^2 is found by π×4.27x²=

On a calculator \pi \times 4.27^2 is found by π×4.27x²=

## Software/Applets used on this page

## Glossary

### circle

a conic curve with equation (x-a)²+(y-b)²=r²

### 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 | G17: Circles, Further and Composite Shapes | Circles | - |

CIE IGCSE (9-1) Maths (0626 UK) | 4 Mensuration | B4.3 Calculations with Circles | Circles | - |

Edexcel GCSE (9-1) Foundation (UK) | G: Mensuration and Calculation | G17: Circles, Further and Composite Shapes | Circles | - |

GCSE Foundation (UK) | Geometry | Perimeter area volume | Circles | - |

OCR GCSE (9-1) Foundation (UK) | 10: Mensuration | 10.03d: Area of a Circle | Circles | - |

Universal (all site questions) | P | Perimeter area volume | Circles | - |