 |
| First, we make pairs of horizontal and vertical lines. |
| We build a horizontal or vertical line between a pair of fixed points, and then map that
line to the middle of the square. |
| Although we can make the line on the side of the square
without making the line in the middle, we cannot make the line in the middle without also making
a line on the side. | |
 |
| Next, we make pairs of parallel slanted lines. |
| Instead
of taking the fixed points on the ends of the side of a square, we take them on the
ends of a diagonal. |
| Can either of these lines be generated without making the other? |
|
| Are there other possibilities? How can we tell? |