Bro. Karen Kidd's paper, "The 47th Proposition of Euclid Made Easy," explores the significance of the 47th Proposition, commonly associated with right triangles, within Masonic teachings. It emphasizes that this mathematical principle, represented as A² + B² = C², symbolizes the interconnectedness of individuals, both within Freemasonry and the broader human community. Kidd highlights that while the Proposition has historical roots predating Euclid, its moral implications are crucial for speculative Masons. The paper references Bro. C.C. Hunt's insights, which articulate that true brotherhood transcends selfish desires, aligning personal welfare with the welfare of others. The discussion underscores the importance of applying the Proposition's principles to moral conduct, suggesting that understanding our relationships can lead to a more virtuous life. The paper serves as a reminder of the ethical responsibilities Masons hold towards one another and humanity at large, reinforcing the idea that individual actions impact the collective well-being.
Karen Kidd – United States
December 17th, 2025
February 28th, 2026
manual
symbolism and_philosophy
Short Papers Competition 2009
© 2010 Internet Lodge and the author
Paper 8/2009
Title The 47th Proposition of Euclid Made Easy
Author Bro Karen Kidd – United States
The 47 th Proposition of Euclid is in the Past Master’s jewel in a number of Masonic Obediences,
Many Brothers point out the Proposition was known long before Euclid, or Pythagoras by whom it
often also is called. Right triangles are part of megalithic monuments built several thousand years
ago in Ancient Egypt and Northern Europe, suggesting those builders understood the Proposition.
However, many Brothers cannot easily explain t he Proposition’s importance to Freemasonry. It is
simple:
A
2 + B2 = C2,
3 +
4 = 5
bro. A + bro. B = bro. C.
At first glance, these figures, and brothers, have no relation at all. The Proposition is important
because it reveals the interrelation between these numbers and these brothers.
It states that in any right triangle, the square of the triangle’s base, or level, (A) added to the square of
the upright (B) will equal the square of the third, longest, side called the “hypotenuse” (C).
Let’s say A = 3 and B = 4
3 x 3 = 9
4 x 4 = 16
9 + 16 = 25
The level is 9, the upright 16 and the hypotenuse, 25.
Therefore, 3 + 4 = 5
Freemasonry hints often at this. In the First Degree, the C* approaches the ar by Irr Sps. In those
Obediences where this approach is practiced, the 3, 4 and 5 are veiled but visible, along with the
level and upright with which each sp begins and ends.
So what is the Proposition’s importance to Freemasonry? The answer, my Brothers, is that we are
not operative but speculative Masons. Therefore, we apply this Proposition to our morals.
Short Papers Competition 2009
© 2010 Internet Lodge and the author
I believe the late Bro. C.C. Hunt stated it best in his own paper, “The Forty-Seventh Problem of
Euclid”:
“So it is in life. Measured on the level of our lower natures, there is no relation between
our own desires and our brother’s needs. We are connected, it is true, as the sides of
a triangle are connected, but there is no reason we should not use him for the
accomplishment of our own selfish purposes, irrespective of his welfare. It is only when
we square our lives by the square of virtue, and our selfish desires are raised to
spiritual purposes, that we perceive that our own welfare is intimately connected with
that of our brother. His misfortunes are our misfortunes, as we can no more injure him
and not be ourselves harmed thereby, than we can strike off our right hand and be
none the worse by reason thereof.”
I think it significant that Bro. Hunt, when he says “brother” in this passage, does so with a small “b”.
For the Proposition shows our interrelation not only with our Brothers in the Craft, but within the larger
brotherhood of all mankind.