Quadrilateral Surprise!

Author:Tim Brzezinski

How would you put this property (dynamically illustrated below) into words? (Applet works best if quadrilateral is kept convex.) How can you formally prove what this applet informally illustrates?

Quick (Silent) Demo

New Resources

GeoGebra Notes
Converting Between Degrees and Radians
Proof of a Rhombus by Construction and Deduction
גיליון אלקטרוני להעלאת נתוני בעיה ויצירת גרף בהתאם
Vector Projections

Discover Resources

princess peach geogebra video game script
AUntitled
Matrix Transform 2
Triangle Congruence Criteria Recap
Function Transformations

Discover Topics

Vectors 2D (Two-Dimensional)
Line Segment
Conditional Probability
Pythagoras or Pythagorean Theorem
General Quadrilateral