This command draws a curve from a perpendicular tangent line
with a known radius and chord length. It prompts for the radius,
the chord length and then to pick the P.C. start point of the curve
and a point along the tangent line.
Precede radius with - sign for curve to the left.
Radius of Arc <300.0000>: press Enter
Chord Length <25.0000>: press Enter
PC
Start Point ?
Pick point or point number: pick a point
[nea on] Pick point along perpendicular tangent line:
pick a point
(5142.38 4911.57 0.0)
Radius Point Coordinates: (5221.51 5209.63 0.0)
Pulldown Menu Location: Draw > Arc
Keyboard Command: SRCL
Prerequisite: Tangent lines should be drawn before
execution