A plane curve is a curve that lies in a single plane. A plane curve may be closed or open. Curves which are interesting for some reason and whose properties have therefore been investigates are called "special" curves (Lawrence 1972). Some of the most common open curves are the line, parabola, and hyperbola, and some of the most common closed curves are the circle and ellipse.
Uncensored Doujin Batch - Chapter 5
Planar Graph -- from Wolfram MathWorld
Chapter 2 Pi in Mathematics and the Physical World in: Pi (π) in
PPT - Day 2 Differential Equations PowerPoint Presentation, free
Finally We May Have a Path to the Fundamental Theory of Physics
The projection point geodesic grid algorithm for meshing the
EvoluteCurve Wolfram Function Repository
A Wolfram Language Approach to Real Numerical Algebraic Plane
Node-Gosper Curve-Based Unknown Sensor Localization Using Single