If we take a cross-section through a pyramid we get a triangle. The Great Pyramid is called Egyptian Triangle, the Triangle of Price, or the Kepler triangle. This triangle  supposedly  contains the golden ratio. In particular, the ratio of the slant height to half the base is said to be the golden ratio. If we compute the value for the sides of the Egyptian triangle, their ratio is 1 : sqrt(Phi) : Phi
But, it is hard to know that the golden ratio was intentionally built into the Great Pyramid or other architecture.
 

Even from the time of the Greeks, a rectangle whose sides are in the "golden proportion" has been known since it occurs naturally in some of the proportions of the Five Platonic. This rectangle is supposed to appear in many of the proportions of that famous ancient Greek temple in the Acropolis in Athens, Greece.
 

The Medieval builders of churches and cathedrals approached the design of their buildings in much the same way as the Greeks. They tried to connect geometry and art.
Inside and out, their building were intricate construction based on the golden section.
 

In 1950, the architect Le Corbussier published a book entitled "Le modulator. Essai
sur une mesure harmonique a l'echelle humaine applicable universalement a l'architecture et a la mecanique ". He invented the word "modulator" by combining "modul" (ratio) and "or" (gold); another expression for the well-known golden ratio.