Individual #projective_geometry__descriptive_geometry__descriptivegeometry  the geometry of properties that remain invariant under projection
  >part of:  geometry  the pure mathematics of points and lines and curves and surfaces
     >part of:  pure_mathematics  the branches of mathematics that study and develop the principles of mathematics for their own sake rather than for their immediate usefulness
        >part of:  mathematics__math__maths__math  a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement

No statement uses or specializes projective_geometry; click here to add one.