How do you calculate sq miles? - Answers

It depends on the shape of the area. For squares and other rectangles it is the product of the length and the width of the area. For circles it is the product of pi and the square of the radius. For triangles it is the product of half of the base and the height. Other regular polygons have their own area equations. For irregularly shaped areas, like countries, you can approximate the area by dividing the area into a bunch of rectangles and calculating the sum of the areas of all of the rectangles, or, if you have a picture of the area that is drawn to scale, you can cut out the shape from a material of known thickness and density and weigh it. Then compare the weight of the irregular shape to the weight of a reference rectangle cut from the same material. The weights will be directly proportional to the areas.