a
are
Areaexact by definition
The are is exactly 100 square metres, a square ten metres on a side. It is the parent unit of the hectare, which is simply one hundred ares, and it survives in continental European land records and in some horticultural and viticultural contexts.
| 1 a | 100 m² |
Where the unit came from
It was created in the French metric reform of 1795 as the intended unit of land measure. The hectare, its hundredfold, turned out to be the size people actually needed, and the are was left behind almost everywhere except in the name of its own multiple.
Solvers that use area