# GeoGebra

## Centers of a Triangle

This applet demonstrates the four basic "centers" of a triangle, as well as some relationships between them, as well as the midsegments. This was created for a basic high school geometry course.

(On GeoGebraTube)## Congruent or Supplementary

This applet allows students to practice identifying pairs of angles formed by parallels and a transversal as congruent or supplementary.

(On GeoGebraTube)## Finding Pi from Polygons

This animation illustrates the use of perimeters of polygons with increasing numbers of sides to estimate pi. It is also useful for illustrating the notion of limits to a pre-calculus class.

(On GeoGebraTube)## Trigonometric Ratios in a Circle

This demonstration shows the relationship between the six basic trigonometric ratios and a unit circle.

(On GeoGebraTube)