File talk:PointToLineDistance v2.png

This diagram contains several errors.

1) The label for c is inverted. The higher the value of c in aX+bY+c=0, the more negative that zero point is. This is easy to discern by picking a simple example (X=0, C=10) and solving for Y. a*0 + bY + 10 = 0  bY = -10

2) The label for c also ignores that it is scaled by a and b. See the trivial example in point #1.

3) The label for aX and bY are incorrect. Let's evaluate the example formula to see this in action.

4) The line shown does not match the example formula: 3x+5y+7=0. That formula results in a line that tilts downwards, not upwards. This is shown by solving for y. 3x+5y+7 = 0  5y = -3x - 7  y = (-3/5)x - 7/5 This shows that the rise over run is -3 over 5. For every 3 units downwards, we need to move 5 units to the right. Correspondingly, we see that the labels for aX and bY (point #3) are incorrect as well. The lateral movement (the run labeled aX) is 5, while the vertical movement (the rise, labeled bY) is -3. These are backwards from what is written.

Not only is this example unfinished and not to scale, but it's misleading and confusing. I would recommend removing it entirely.