What is projection for Flatland?

Center of projection/ perspective.

[ compare with similarity].

Correspondences: Activity:Circle to Line:

How to see the Infinite using Projective geometry.

Circle to line and line to Circle!

Line to Line

Perspective and projective relations between points on lines.

Perpective between planes in Space!

Seeing the horizon on a plane.... a line of ideal/infinite points.

How parallel lines "meet" on the horizon.

What is the Projective Plane?

Desargues' Theorem.