# Brahmagupta’s formula

If a cyclic quadrilateral^{} has sides $p,q,r,s$ then its area is given by

$$\sqrt{(T-p)(T-q)(T-r)(T-s)}$$ |

where $T=\frac{p+q+r+s}{2}$.

Note that if $s\to 0$, Heron’s formula is recovered.

Title | Brahmagupta’s formula |

Canonical name | BrahmaguptasFormula |

Date of creation | 2013-03-22 11:44:19 |

Last modified on | 2013-03-22 11:44:19 |

Owner | drini (3) |

Last modified by | drini (3) |

Numerical id | 11 |

Author | drini (3) |

Entry type | Theorem |

Classification | msc 51-00 |

Classification | msc 81T70 |

Classification | msc 81T25 |

Classification | msc 81T20 |

Classification | msc 81T75 |

Classification | msc 81T05 |

Classification | msc 11-02 |

Classification | msc 05-02 |

Classification | msc 05C30 |

Related topic | CyclicQuadrilateral |

Related topic | HeronsFormula |