Anyone understand this? It comes from an issue of "Science" published in 1930.


1. Sneferu 51" 52' 1. Medum
2. Great Pyramid of Gizeh ..... Khufu 51° 52'
3. Khafra 53° 10'
4. Menkaura 51° 10'
Why did the architect in each case choose an angle of about 52° instead of 45° or 60° ? It is an interesting fact that for a right triangle having a lower angle of 51° 49.6' the height is the geometric mean between the base and the hypothenuse, that is, the ratio of hypothenuse to height is equal to the ratio of height to base, giving a right triangle with perfect proportions the ease of the first two the angle approximates this ideal angle within one part in a thousand. However, the fact that the third and fourth pyramids depart from this angle, one being slightly more and the other slightly less, suggests that the design was not controlled entirely by a mathematical formula, but was subject to modification according to artistic judgment, which, however, oscillated about the value gven by the formula.
Gordon S. Fulcher

Jon