Tangent is the ratio of the opposite to the adjacent sides of any right triangle.
We will use the tangent of an angle to determine baseline. The purpose is to find out where you are on a map by choosing three to four locations on a map. Then you can figure out your location by having the height of the location. Also when you use the formula and figure out by making circles with a compass. You need to know how many feet are in a mile so there are 5280 feet in a mile.