Why is (did) one are = 100 sq. meters?

[woodpusher]

Were the row houses in Paris 10 m x 10 m?

The best I could find was that a square km was too big and a sq m was too small. If something approximating the acre was desired, then they should have let one are = 10000 sq m (the modern-day hectare).

[Johnny_L.A]

I had to look this one up.

are (a)
a unit of area equal to 100 square meters. The word is pronounced the same as “air.” Being the area of a square 10 meters on each side, the are is a little large for measuring areas indoors and a little small for measuring areas outdoors. As a result, the are is not used as often as its multiple, the hectare (ha). One are is approximately 1076.3910 square feet, 119.5990 square yards, or 0.02471 acre.

ISTM that it’s a logical unit for the metric system. One square meter is 1 x 1, one are is 10 x 10, and one hectare is 100 x 100.