Can anyone explain this??
Solution:
An are (a) is a derived metric SI (System International) measurement unit of area used to measure land with sides equal to ten meters (10m)
A hectare (ha) is a derived metric SI (System International) measurement unit of area used to measure land with sides equal to one hundred meters (100m)
A square kilometer (km²) is a derived metric SI (System International) measurement unit of area with sides equal to one kilometer (1km)
A square centimeter (cm²) is a derived metric SI (System International) measurement unit of area with sides equal to one centimeter (1cm)
A square millimeter (mm²) is a derived metric SI (System International) measurement unit of area with sides equal to one millimeter (1 mm)