Centroid- Intersection of Medians.
Centroid or Barycenter
Change triangle to obtuse, right and back to acute. What happens to the centroid? Is it in the triangle, on the triangle or outside the triangle?
Circumcircle or Circumscribed Circle
Incircle or Inscribed Circle
Related Rates: Area of a Circle
The Quadratic Formula as the Axis of Symmetry & Distance
Mamikon's Pythagorean Proof