So .16293/65 bars = .00250662 SCALE.
To calculate the angle farther back on the chart. .04370/24 bars = .00182083333. Now divide that by the scale OR multiply by the scale inverse...and you get .726411. This represents the real y/x for the tan ratio... and arctan or tan inverse = 36 degrees.
These red angle numbers show that you can't just apply any FAN setting to a chart. A 30 degree angle on one chart can be a 60 degree angle on another. Scale also makes a difference in the way the arcs hit 2 points at once. Draw a from a center to a point and watch what happens to the other points that the arc touches. They move and don't fit the . This is actually useful because with the proper scaling as in this chart...you can find consistent radius distance relations...and even when changing the overall size, there is still a ratio relation between the arcs. ie. arc 1= .72 (usually .764) and arc 2 = 1 etc.