Euclid and three line segments

Three line segments
Pleaded to Euclid

First asked
Its endpoints connected
Euclid obliged
Becoming a circle
Rolled away
Desultory

Second asked
One endpoint removed
Euclid obliged
Becoming a point
Remained forever
Desolate

Third asked
One endpoint inserted
Euclid obliged
Becoming a triangle
Realized stability
Determined