Manual

Geometry 171
perpendicular
Draws a line through a given point that is perpendicular to a
given line. The line may be defined by its name, two points,
or an expression in x and y.
perpendicular(point, line) or
perpendicular(point1, point2, point3)
Examples:
perpendicular(GA, GD) draws a line perpendicular to
line D through point A.
perpendicular(3+2i, GB, GC) draws a line through
the point whose coordinates are (3, 2) that is perpendicular
to line BC.
perpendicular(3+2i,line(x–y=1)) draws a line
through the point whose coordinates are (3, 2) that is
perpendicular to the line whose equation is x – y = 1; that is,
the line whose equation is y=–x+5.
segment
Draws a segment defined by its endpoints.
segment(point1, point2)
Examples:
segment(1+2i, 4) draws the segment defined by the
points whose coordinates are (1, 2) and (4, 0).
segment(GA, GB) draws segment AB.
tangent
Draws the tangent(s) to a given curve through a given point.
The point does not have to be a point on the curve.
tangent(curve, point)
Examples:
tangent(plotfunc(x^2), GA) draws the tangent to the
graph of y=x^2 through point A.
tangent(circle(GB, GC–GB), GA) draws one or more
tangent lines through point A to the circle whose center is at
point B and whose radius is defined by segment BC.