A square inch (sq in or in²) is a unit of area commonly used in the United States and other countries that use the imperial system of measurements. It is defined as the area of a square with sides that each measure one inch in length.
In terms of square centimeters, one square inch is approximately equal to 6.4516 square centimeters (cm²).
Square inches are used in various applications, especially for measuring small areas, such as the size of a sheet of paper, the dimensions of electronic devices, or the area of specific objects or surfaces in everyday life.
A square kilometer (often abbreviated as km²) is a unit of area in the International System of Units (SI). It represents a square with sides that each measure 1 kilometer in length.
One square kilometer is equal to 1,000,000 square meters (m²) because there are 1,000 meters in a kilometer, and when you square that length, you get 1,000 * 1,000 = 1,000,000 square meters.
To visualize the size of a square kilometer, you can imagine a square plot of land, each side of which measures 1 kilometer (approximately 0.621 miles). It's a commonly used unit to measure land area, particularly in countries that use the metric system.