# GeoArea

GeoArea[g]

gives the area of the geo region g.

# Details and Options • GeoArea[Polygon[]] computes the area enclosed by the polygon, assuming that neighboring points of the polygon are joined by geodesic paths.
• GeoArea[Polygon[entity]] and GeoArea[entity] compute the area enclosed by the polygon of the given geo entity.
• GeoArea[{g1,g2,}] returns {GeoArea[g1],GeoArea[g2],}.
• GeoArea["World"] returns the area of the surface of the Earth, using the ellipsoidal model "ITRF00".
• Possible options of GeoArea include:
•  GeoModel Automatic model of the Earth or celestial body UnitSystem \$UnitSystem unit system to use in the result

# Examples

open allclose all

## Basic Examples(3)

Compute the area of the polygon of the United States:

Compute the area of the latitude-longitude rectangle enclosing the United States:

Compute the area of a geo disk centered at your geo location:

## Scope(7)

Compute the area of a polygonal region on Earth, assuming geodesic edges:

Compute the area of the region enclosed by the polygon of a geo entity:

That can also be expressed as follows:

Areas of the entities of a class, in this case the countries of South America:

Total area of the polygon enclosing those countries:

Surface area of the Earth:

Area of 2D geo primitives:

Area of a region with holes:

It can also be obtained by subtracting the areas of the inner regions from that of the outer region:

Total area of a group of non-overlapping geo regions:

It can also be obtained by computing the respective areas and adding them:

## Options(2)

### UnitSystem(1)

Use the units determined by the value of \$UnitSystem:

Specify the unit system to use:

### GeoModel(1)

Area of a region of Earth:

Area of the area delimited by the same parallels and meridians on Mars:

## Properties & Relations(3)

The ratio of area to squared radius decreases, due to the curvature of the Earth:

GeoArea computes area on the surface of the ellipsoidal Earth:

Use Area with the projected polygon to compute area on the flat map:

"UTMZone33" is an appropriate transverse Mercator projection for Austria, and produces a relative error smaller than :

Using an inconvenient projection, like "UTMZone48", may result in large area errors:

GeoArea returns Missing["NotAvailable"] for those entity objects with no polygon information:  Missing expressions are propagated:

Introduced in 2015
(10.3)