[3 Tangents] command generates an arc, with three contacting curves specified.
For the prompt
"Specify the first base curve."
, specify a curve where the generating
arc contacts at the end.
For the prompt
"Specify the second base curve."
, specify a curve where the generating
arc contacts at a through point.
For the prompt
"Specify third base curve."
specify a curve where the generating arc contacts at the other end.