The Department of Mathematics Education

Jim's GSP Library

Last modified on August 27, 2008.

1. Centroid of a triangle
2. Orthocenter of a triangle
3. Circumcenter of a triangle
4. Circumcenter of a triangle as a point equidistant from each vertex
5. CIRCUMCIRCLE of a triangle
6. Incenter of a triangle
7. INCIRCLE of a triangle
8. Rectangle circumscribed about an ellipse. As a changing rectangle is rotated about an ellipse so that the sides of the rectangle are always tangent to the ellipse, the vertices move along a common circle.
9. Rectangle circumscribed about an ellipse. Another version of the rotating rectangular region about the ellipse.
10. Parabola. The parabola is the locus of points equidistant from a fixed point (the Focus) and a line (the directrix).
11. Pentamotion. Constructing and moving concentric pentagons.
12. Fourth Proportional. Given three line segments a, b, and c, construct the fourth proportional, a segment of length x such that a/b = c/x.
13. Hyperbola Triangle. A moving tangent to the hyperbola intersects the asymptotes to define a triange of a constant area.
14. Circles of Apollonius. This sketch shows the Circles of Apollonius for a given triangle ABC. The three circles pass through two points common to all three circles.
Back to Syllabus.
Back to EMAT 6680 Home Page.
Back to Jim Wilson's Home Page.

Send e-mail to