One can slightly move the yellow point and see what happens.

This is an arrangement of 15 lines on real projective plane with
disconnected

moduli space. The moduli space is parametrised by the position of point
"P"

on line "a".The arrangements are combinatorially the same when
"P" is located slightly to the right or left relatively

to the red point. But it degenerates if "P" is equal to the red
point. In this situation

the triangle formed by lines "a", "r" ,
"o" degenerates
to point.

Such an effects are usually very subtle and it is difficult to scale the
picture to make it visionable.

In our Cinderella mechanism the critical triangle is homotetically
enlarged to
the red one.

Also badly visionable triangle "r", "k" ,
"n" is enlarged to
the green one.

Created with Cinderella