1. Points, Lines, and Planes
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Note that a room with four walls, a floor, and a ceiling only gives you 6 planes.
An example of the living room in our newly designed apartment is shown below. It has a floor, labeled H, and seven different wall-sections named A, B, C, D, E, F, and G.
Note that C and G, even though they are not connected, belong to the same plane. Therefore, in total, we have 7 different planes when counting the walls and the floor. If we add the ceiling to our number of planes, we reach a total of 8, just as we wanted.