# MI_Perimeter

## Description

Returns the geographic perimeter of a geometry object.

## Syntax

MI_Perimeter ( geometry, unit, calculationType )

## Arguments

`geometry` is an expression which returns a geometry,

`unit` is a linear unit specification, and

`calculationType` is a string that indicates whether to perform a Spherical or Cartesian calculation. There is no default.

## Example

Selects the countries and returns the perimeter for counties that start with 'Ar'.

`select Country from countries where MI_Perimeter(Obj,'km','Spherical') AND Country like 'Ar%'`

## Remarks

The value returned is a double and represents a value in the units specified by the `units` argument. MI_Perimeter is applicable only to geometries of type Envelope, Polygon, Multipolygon, and Ring. Any other type of input geometry results in a value of zero.

Valid values for `unit` are the following distance units:

Value | Description |
---|---|

mi | miles |

km | kilometers |

in | inches |

ft | feet |

yd | yards |

mm | millimeters |

cm | centimeters |

m | meters |

survey ft | US Survey feet |

nmi | nautical miles |

twip | twips |

pt | points |

pica | picas |

degree | degrees |

li | links |

ch | chains |

rd | rods |