Below you find a triangle with the option to visualise certain special points and lines in a triangle.[br]The triangle's vertices can be dragged to form different triangles.[br][br]Experiment with the different lines and their intersections. [br]The special circles for the triangle you can look at (incircle and circumcircle will be studied later in the lecture)

Here are some questions that you can think about....[br]1. The orthocenter is the intersection of the altitudes. [br] How do triangles look like whose orthocenters lie outside of the triangle[br]2. The centroid (center of gravity) splits each median into a certain ratio. What is the ratio and why is it so?[br]3. Can the centroid lie outside of the triangle?[br]4. Are there three of the centers which are collinear for all triangles?