There are several ways you can approach this problem. One approach that doesn't work well is to use slope-intercept equations of the form y = m × x + b for the lines. The problem with that approach is that it doesn't work for vertical lines. If a line is vertical, then the equation's slope, m, is effectively infinite.
The approach that I use defines a line by giving a point p0 on the line and a vector v that points in the direction of the line. Then the following equation defines the points on the line:
Here, t is any real number. For example, if t = 0, then the point is p0.
This is a parametric equation. In a ...
