x, y, z coordinates

In this chapter we’re going to be looking at coordinates. The x, y, and z coordinates on a graph. The graph below shows the x and y coordinates.

Any graph has four different regions where x and y-coordinates are either positive or negative. These regions are shown below.
When noting down the coordinates on a graph you have to always remember that the coordinates are written in alphabetical order. The x-coordinate comes first then the y-coordinate.

You also have to remember that the x-coordinate is along the x-axis which is the horizontal line across the graph. The y-coordinate is the axis which is the vertical line in the graph.
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Z coordinates

x and y coordinates are in 2-D (flat) while coordinates with a z-coordinate are in 3D. The world is in 3D and not 2D. You can zoom in, move sideways, or move up and down. This is why the Z-coordinate is necessary. A graph with the Z-coordinates is shown below.
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All the Z-coordinates do is extend the normal 2-D x-y coordinates by giving it a third direction so that all positions then have 3 coordinates (x, y, z).Having 3 coordinates means you can give the coordinates of the ends of a book or any other 3-D shape. An example is shown below.
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For the graph above the coordinates of B are (7, 4, 0) and the coordinates of F are (7, 4, 2)