
Euclid as the Father of Geometry

Language and Notation of Basic Geometry

Area of a Regular Hexagon

Problem involving angle derived from square and circle

Area of a Parallelogram

Proof  Rhombus Area Half Product of Diagonal Length

Proof  Rhombus Diagonals are Perpendicular Bisectors

Proof  Opposite Angles of Parallelogram Congruent

Proof  Diagonals of a Parallelogram Bisect Each Other

Proof  Opposite Sides of Parallelogram Congruent

Quadrilateral Overview

Common Orthocenter and Centroid

Euler's Line Proof

Euler Line

Review of Triangle Properties

Proof  Triangle Altitudes are Concurrent (Orthocenter)

Median Centroid Right Triangle Example