Basic Principles of Geometry

In this lesson, Math Fortress presents and proves two basic theorems in geometry, the right angles theorem and the straight angles theorem.

Follow along to three examples that illustrate how to use previously proven theorems, assumptions, and properties in order to write a geometric proof.

Learn how to identify midpoints, bisectors of segments, trisection points, trisectors of segments, adjacent angles, angle bisectors, and angle trisectors.

In this lesson, continue building basic geometry skills by completing six proofs that explore the division of segments and angles as covered in lesson one.

In this lesson, continue building basic geometry skills by reviewing nine different examples that demonstrate the division of segments and related concepts.