Answer:

A hectare is a measure of area. One hectare is 10 000 square metres, equivalent to the area of a square 100 metres by 100 metres. A hectare is approximately 2 ½ acres, about the size of a rugby pitch.

A square 100 m on each side is one hectare, the most common and convenient SI area multiple used in the surveying profession for day to day legal documents such as land deeds, mortgage surveys, town planning, environmental protection, and other necessary property considerations under the law.

Square kilometers are often too large to work with conveniently, and square meters are similarly too small.