A number line is infinite in both directions. Numbers are a convenient way for people to organize their thoughts about space and time. First we can think of zero as a point, taking up no space at all. Then we begin to count. We can use numbers to count how many people there are, or how many sheep we have. [...]
Pyramid Just as a plane is made of an infinite number of lines, a solid is made of an infinite number of planes. These planes are right next to each other, like a stack of paper. A solid has width, and length, and thickness.If you looked at a solid from the side, it would look [...]
These two green lines are skew to each other. Skew is a pretty cool word, and it sounds like it means something really weird, and it kind of does. It means lines that go any which way. It describes any two lines that aren't either parallel or perpendicular to each other, and that don't cross each other anywhere (so [...]
