Positional problems

A:

  • Point, line, half-line, and line segment
  • Half-plane
  • Angle, pair of angles (corresponding, alternate, adjacent, vertical)
  • Relative position of two lines (parallel, intersecting, perpendicular)

B:

  • Mutual position of line and circle
  • Mutual position of two circles

C:

  • Sets of points with a given property 
  • Thales' circle