(generalized) straight line

With ordinary straight lines, many figures can be composed. We call them polylines:

• crack function
  • discrete curve
• cross
• line spiral
• needle function
  • delta function
• polygon
  • (simple) polygon
    • triangle
    • quadrilateral
    • pentagon
    • hexagon
    • star
  • polygram
    • star figure
    • star polygon

The line can turned into a fractal with the Cantor set.