Geometric Mean Theorem with Area Model

Topic:
Area, Means
Geometric Mean Theorem with Area Model Δ ACB is similar to Δ ADC and Δ CDB since they are formed in a semicircle. Therefore, algebraic similarity gives a/h =h/b and h² = ab. Geometrically, the square with side = h is the same size as the rectangle with sides a and b; i.e., the green square and blue rectangle have equal areas. This diagram also suggests how to construct a square equal in area to a given rectangle. Wikipedia has a nice article with the topic: Geometric mean theorem