Explanation:
A hectare is a (legally recognized in Germany, Austria and Switzerland) unit of measurement for area , which is mainly used in agriculture and forestry. However, this unit of area is not listed in the international system of units (SI). In addition, it always refers to the specification of the size of land and parcels.
One hectare, officially abbreviated as ha , corresponds exactly to an area of 10,000m² or 100Ar (abbreviation: a ).
This in turn could, for example, correspond to a square plot of land 100m by 100m .
The whole thing can be converted as follows:
100 ha = 10,000 a = 1,000,000 m²
1 ha = 100 a = 10,000 m²
0.1 ha = 10 a = 1000 m²
0.0001 ha = 0.01 a = 1 m²