This command fits a curve between two tangent lines and a known arc length. It prompts for the arc length then pick the P.I. (intersection of tangent lines) and points on the two tangent lines.
Arc Length
<100.00>: press Enter or enter
distance
[int on] Pick P.I. of curve: pick intersection of
tangent
lines
[nea on] Pick pnt on 1st Tangent Line: pick
a point
[nea on] Pick pnt on 2nd Tangent Line: pick
a point
Pulldown Menu Location: Draw > Arc
Keyboard Command: 2tanlal
Prerequisite: Tangent lines should be
drawn before execution
File Name: \lsp\2tanlal.lsp