Cut-The-Knot Action 9!

Author:Tim Brzezinski

Creation of this applet was inspired by a tweet from Alexander Bogomolny. Note the rectangles shown are similar to each other. How can you formally prove what this applet informally illustrates?

New Resources

Silhouettes without gaps and isolated
The black friday GeoGebra :)
bewijs stelling van Pythagoras
Domino Chain Reaction
The Cosine Formula - Proof Without Words

Discover Resources

Lattice point with GeoGebra
Central Symmetry
Prove Quad is Parallelogram
square
Треугольник

Discover Topics

Pie Chart or Circle Chart
Median Line
Pythagoras or Pythagorean Theorem
Unit Circle
Geometric Distribution