### 12.7.6 Perpendicular lines in the plane: perpendicular

See section 13.5.6 for perpendicular lines in space.

The perpendicular command takes as arguments either a point and a line, or three points (the last two points determining a line).

perpendicular returns and draws the line perpendicular to the given line passing through the given point.
Input:

perpendicular(0,line(1,i))

or:

perpendicular(0,1,i)

Output: