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

Segment Addition Postulate (Mild Questions)
Perpendicular Lines: Quick Exploration
Congruent Figures
Slope Illustrator (2)
Isosceles Right Triangle

Discover Resources

translations,4
Graphing a line with slope and y-intercept
Exercise 6
Untitled
JST17 10. Section 1b Gradient of a chord on a cubic curve

Discover Topics

Exponential Functions
Coordinates
Logarithm
Perimeter
Means