Please explain why there is no higher latitude than 90 degrees N and 90 degrees S. .
Latitude and longitude are terms used in Geography and they help establish the location of a country, a city or place and are used in navigation systems including the now popular GPS which many people use and in fact rely on to get from one place to another. Measurements using angles describe the position of something remote or something in more direct proximity to where you are. Picture earth as the globe that it is with a grid denoting the lines of latitude running horizontally and the lines of longitude running vertically.
In order to verify the angles 90 deg N or 90 deg S always start at the equator line because this is the line of reference. If you are familiar with the Cartesian Plane (the normal x and y axes) in Math you can see that the equator works like the x axis and the line of longitude to the North or South Pole works like the y axis. Once you reach 90 deg (i.e. a right angle just like the x and y axes create) you will note that you have 90 deg either way- to the left and to the right or, geographically to the west or east. Just as the equator is the reference line for latitude, Greenwich in England is the reference line for longitude. Therefore, with the equator line as 0 deg and a vertical line from the center to the north or south pole, a set of perpendicular lines is created and completes the picture.
it would defeat the object if angles could extend beyond 90 deg because the west and east significance would be lost. This is why, there is no higher measurement than 90 deg N or 90 deg S. Once you get to 90 deg, go back to the equator line and measure your angle from the other direction.
The answer to your question involves simple Euclidean Geometry. The Earth is round (more or less) therefore if viewed on a flat surface, its form would be a circle. A circle is comprised of 360 degrees. The Equator, which divides the world North and South, is at the mid point of that circle, so this divides the circle into two halves of 180 degrees each. In measuring latitude, one begins at the Poles, which are at zero degrees and 180 degrees, similar to the Equator, only they are drawn at right angles to the Equator itself. A line from the North Pole to the South Pole, will, with the Equator, divide the world into four equal parts, each of which will be 90 degrees on the arc created. So, if one measures from the North Pole at zero degrees to the Equator, one measures 90 degrees. Again, when one measures from the South Pole at 180 degrees to the equator, one again measures 90 degrees. If we treat the Equator as zero degrees latitude, then the distance (or angle) to each pole is 90 degrees. North or South depends on the direction in which one is moving. Hope this helps.