My question is related to the coordinates used for the "line" function. In school, I learned that for an xy plot, positive values for both x and y would put the coordinates of a given point in the "upper right" quadrant (hopefully that makes sense).
For example, the code below I would expect a line at x1=30, y1=20, x2=85, y2=75 to have a positive slope
However, it gives a negative slope. (where slope is defined as rise/run)
So my question is which direction does a positive y value cause a drawing to go - up or down?
