Average of areas - quadratic mean
- Author:
- Vincent Pantaloni
- Topic:
- Area, Geometry, Means, Pythagoras or Pythagorean Theorem, Square
GIF animation

GeoGebra applet
The green square's area is the average of the blue and yellow square's area. In other words, if the side of the blue square is a, and that of the yellow square is b, the green square has a side which is q, the quadratic mean of a and b :