Convert Square Millimeter to Hectare

The square millimeter is derived from the millimeter, which is a unit of length in the metric system. The millimeter itself is one thousandth of a meter and was introduced as part of the metric system in the 18th century. The square millimeter is defined as the square of the millimeter, and it follows the principles of the metric system, where area units are derived from the square of the unit of length. As the metric system became more widely adopted globally, the square millimeter became a standard unit for measuring very small areas, especially in fields such as engineering, electronics, and printing.

The hectare was introduced in the 18th century as part of the metric system and is derived from the meter, the base unit of length in the metric system. The word "hectare" comes from the Greek word "hekaton" meaning "hundred," combined with the metric unit "are" (which represents 100 square meters). The hectare was designed to provide a practical unit for measuring larger areas, such as farmland and forests, in a way that fits within the metric system. Today, the hectare is widely used across the world for land measurement, although it is not commonly used in the United States, where acres are preferred instead.