Geodetic Areas
Compute areas of geodesic polygons on the Earth, using the default ellipsoidal model.
Area of a geodesic triangle on the Earth.
In[1]:=
![Click for copyable input](assets.en/geodetic-areas/In_20.png)
polygon = Polygon[GeoPosition[{{0, 0}, {0, 90}, {90, 0}}]]
Out[1]=
![](assets.en/geodetic-areas/O_12.png)
In[2]:=
![Click for copyable input](assets.en/geodetic-areas/In_21.png)
GeoArea[polygon]
Out[2]=
![](assets.en/geodetic-areas/O_13.png)
In[3]:=
![Click for copyable input](assets.en/geodetic-areas/In_22.png)
GeoArea[polygon];
% == GeoArea["World"]/8
Out[3]=
![](assets.en/geodetic-areas/O_14.png)
Area of a continent.
In[4]:=
![Click for copyable input](assets.en/geodetic-areas/In_23.png)
polygon = EntityValue[Entity["GeographicRegion", "Africa"], "Polygon"]
Out[4]=
![](assets.en/geodetic-areas/O_15.png)
In[5]:=
![Click for copyable input](assets.en/geodetic-areas/In_24.png)
GeoArea[polygon]
Out[5]=
![](assets.en/geodetic-areas/O_16.png)
Land area in the world.
In[6]:=
![Click for copyable input](assets.en/geodetic-areas/In_25.png)
polygon = EntityValue[Entity["GeographicRegion", "World"], "Polygon"];
In[7]:=
![Click for copyable input](assets.en/geodetic-areas/In_26.png)
GeoArea[polygon]
Out[7]=
![](assets.en/geodetic-areas/O_17.png)
Less than 29% of the Earth's surface is land.
In[8]:=
![Click for copyable input](assets.en/geodetic-areas/In_27.png)
GeoArea[polygon];
%/GeoArea["World"]
Out[8]=
![](assets.en/geodetic-areas/O_18.png)