Manual

178 Geometry
incircle
Draws the incircle of a triangle, the circle tangent to all three
sides of the triangle.
incircle(point1, point2, point3)
Example:
incircle(GA, GB, GC) draws the incircle of ΔABC.
locus
Given a first point and a second point that is an element of (a
point on) a geometric object, draws the locus of the first point
as the second point traverses its object.
locus(point,element)
parabola
Draws a parabola, given a focus point and a directrix line, or
the vertex of the parabola and a real number that represents
the focal length.
parabola(point,line) or parabola(vertex,real)
Examples:
parabola(GA, GB) draws a parabola whose focus is point
A and whose directrix is line B.
parabola(GA, 1) draws a parabola whose vertex is point
A and whose focal length is 1.
Transform
dilation
Dilates a geometric object, with respect to a center point, by
a scale factor.
homothety(point, realk, object)
Example:
homothety(GA, 2, GB) creates a dilation centered at
point A that has a scale factor of 2. Each point P on geometric
object B has its image P’ on ray AP such that AP’=2AP.