4. In the Poincaré model of non-Euclidean geometry,
the geodesic lines are the arcs interior to
the unit circle perpendicular to its boundary.
Define a method with point P as
argument that constructs the arc
with P as centre, orthogonal to the unit circle.
4. Design a pair of routines ne_moveto(P),
ne_lineto(P)
that draws a non-Euclidean geodesic segment between two
points inside the unit circle.
Hint. How do you draw the non-Euclidean arc from a point P
to another point Q? How about the easiest case, when they are on the unit
circle itself?
