Hectare

The hectare ( /ˈhɛktɛər/ or /ˈhɛktɑr/; symbol ha) is a metric unit of area defined as 10,000 square metres (100 m by 100 m), and primarily used in the measurement of land. In 1795, when the metric system was introduced, the 'are' was defined as being 100 square metres and the hectare ('hecto-' + 'are') was thus 100 'ares' or 1/100 km2. A hectare of land is about 2.47 acres.