Overview of the particular lines of the triangle – GeoGebra

Parallel Lines Triangle Proportion – GeoGebra

Triangle Construction – GeoGebra

Was fooling around with Geogebra and found this. I didn't see

Special lines in Triangles – GeoGebra

Points of Concurrency – GeoGebra

Special points and lines in a triangle – GeoGebra

G.2.4.2 What Information Do I Need? – GeoGebra

Types of Triangles(By Sides and Angles) – GeoGebra

Interactive Triangle – GeoGebra

Altitudes in a Triangle – GeoGebra

GeoGebra Workshop - Salisbury University

Incircle of a triangle – GeoGebra

Exploring Right Triangles – GeoGebra

Area of a Triangle – GeoGebra

Concurrent Lines in a Triangle – GeoGebra