Geometry has to do with the arcs and angles of thrusts and parries. The object was to make fencing a physical exercise with mathematical precision, I am not sure how they did this, but firing large guns on land or sea to hit specific targets also involves geometry.
Until the 1840's, the Universidad de Salamanca had a Department of Astrology. Not astronomy, astrology. The Holy Mother Church, of course, opposed astrology, except in the one instance in which the Tres Reyes Magos (three wise men) were said to be guided by the Star of Bethlehem. The word used for then in Spanish is Three Magician Kings, or Kings of Magic. The magic involved was astrological fortunetelling.
Of course, the Bible does not say there were three wise men. It says there were three gifts, and it was therefore assumed that this involved three gift givers. The word in the Bible is plural, so there had to be at least two of them. The Bible likes the idea of things that come in threes, The Trinity, Faith, Hope and Charity, Jesus Mary and Joseph. It is like the Monty Python bit about the Holy Hand Grenade. Three is the basis of trigonometry and the Pythagorean Cult as well.
Strangely, although the Bible indicates that they were guided by a star, it also states that they had to speak with King Herod to get complete directions.
The whole tale is fishy.
