An "are" (symbol: a) is a unit of area that is not part of the International System of Units (SI) but is used in some countries, particularly in Europe, for measuring land areas. One are is equal to 100 square meters (m²).
To put it simply, 1 are is equivalent to a square with sides that each measure 10 meters. It is a relatively convenient unit for measuring smaller land areas, such as gardens, small fields, or land plots, where using square meters might result in large numbers.
Here are some additional conversions to provide context:
For example, if you have a piece of land that is 5 ares in size, it would be equivalent to 500 square meters (5 ares * 100 m²/are = 500 m²).
A square decameter (often abbreviated as dam²) is a unit of area in the International System of Units (SI). It represents a square with sides that each measure 10 meters (1,000 centimeters) in length.
One square decameter is equal to 100 square meters (m²) because each side of the square is 10 meters long, and when you square that length, you get 100 square meters.
Square decameters are not as commonly used as some other units of area, but they can be used to describe moderate-sized land areas, and they are a part of the metric system for measuring area.