# Coolidge's formula (area of a general convex quadrilateral)

## Description

A quadrilateral is a polygon with four sides (or edges) and four vertices or corners. Coolidge’s formula calculates the area of a general convex quadrilateral of the sides, the semiperimeter and the lengths of the diagonals of the quadrilateral.

Related formulas## Variables

A | The Area of the quadrilateral (m^{2}) |

s | The semiperimeter of the quadrilateral (a+b+c+d)/2 (m) |

a | Side of the quadrilateral (m) |

b | Side of the quadrilateral (m) |

c | Side of the quadrilateral (m) |

d | Side of the quadrilateral (m) |

p | One of the diagonals of the quadrilateral (m) |

q | The other giagonal of the quadrilateral (m) |