Curated OER
Properties of the Centers of a Triangle
High schoolers investigate properties of the four centers of a triangle and explore a special property of the circumcenter and orthocenter of a triangle. This instructional activity requires the use of Cabri, Jr.
Curated OER
The Search for Pythagoras' Treasure
Students identify and define properties of triangles. In this geometry lesson plan, students identify the missing sides and angles of right triangles. They use the rules of the Pythagorean Theorem to solve their problems.