The position of a place on the earth`s surface .
Let us take a large ball and mark two points on it so that they are exactly opposite to each other . now draw a line right round the ball so that it is midway between the points all the way . the line will now divide the ball into tow equal parts , and ,becauae the ball is a sphere , each part can be called a hemisphere . we will now call the line the equator and you will see that it is a circle . one point we will call the north pole and the other the south pole .