Perpendicular lines and planes in space

See Section 26.6.6 for perpendicular lines in the plane.

The perpendicular command can take its arguments in different ways. It returns and draws a line or plane, depending on the arguments.

With a point and a line.
- perpendicular takes two arguments:
  - P, a point.
  - L, a line.
- perpendicular(P,L) returns and draws the line through P that is perpendicular to L.
With a line and a plane.
- perpendicular takes two arguments:
  - L, a line.
  - P, a plane.
- perpendicular(L,P) returns and draws the plane containing L that is perpendicular to P.

perpendicular(point(0,0,0),line(point(1,0,0),point(0,1,0)))

perpendicular(line(point(0,0,0),point(1,1,0)), plane(point(1,0,0),point(0,1,0),point(0,0,1)))