Support and Resistance lines need not be Horizontal only. Neither need they be Parallel.
The SIMPLEST way to demonstrate a relationship between TWO POINTS is to draw a straight line between them. Horizontal S&R Lines demonstrate common Highs and Lows, and Opens and Closes. This is meaningful because Price tends to respect these same lines again and again.
Another important relationship is between each mini-trend up or down, or at an angle, and the Price each trend points to, which tends to be a swing high or low. So when examining the following chart, consider how much information AND VERIFICATION each mini-trend gives to us.