Triangle. There is no symbol more important in its signification, more various in its application, or more generally diffused throughout the whole system of Freemasonry, than the triangle. An examination of it, therefore, cannot fail to be interesting to the Masonic student.
The equilateral triangle appears to have been adopted by nearly all the nations of antiquity 
as a symbol of the Deity, in some of his forms or emanations, and hence, probably, the prevailing influence of this symbol was carried into the Jewish system, where the yod within the triangle was made to represent the Tetragrammaton, or sacred name of God.
as a symbol of the Deity, in some of his forms or emanations, and hence, probably, the prevailing influence of this symbol was carried into the Jewish system, where the yod within the triangle was made to represent the Tetragrammaton, or sacred name of God.The equilateral triangle, says Bro. D. W. Nash, (Freem. Mag., iv 294,) "viewed in the light of the doctrines of those who gave it currency as a divine symbol, represents the Great First Cause, the creator and container of all things, as one and indivisible, manifesting himself in an infinity of forms and attributes in this visible universe."
Among the Egyptians, the darkness through which the candidate for initiation was made to pass was symbolized by the trowel, an important Masonic implement, which in their system of hieroglyphics has the form of a triangle. The equilateral triangle they considered as the most perfect of figures, and representative of the great principle of animated existence, each of its sides referring to one of the three departments of creation, the animal, vegetable, and mineral.
The equilateral triangle is to be found scattered throughout the Masonic system. It forms in the Royal Arch the figure within which the jewels of the officers are suspended. It is in the ineffable degrees the sacred delta, everywhere presenting itself as the symbol of the Grand Architect of the Universe. In Ancient Craft Masonry, it is constantly exhibited as the element of important ceremonies. The seats of the principle officers are arranged in a triangular from, the three lesser lights have the same situation, the square and compass form, by their union on the greater light, two triangles meeting at their bases. In short, the equilateral triangle may be considered as one of the most constant forms of Masonic symbolism.
The right-angled triangle is another form of this figure which is deserving of attention. Among the Egyptians it was the symbol of universal nature; the base representing Osiris, or the male principle; the perpendicular, Isis, or the female principle; and the hypotenuse, Horus, their son, or the product of the male and female principle.
Among the Egyptians, the darkness through which the candidate for initiation was made to pass was symbolized by the trowel, an important Masonic implement, which in their system of hieroglyphics has the form of a triangle. The equilateral triangle they considered as the most perfect of figures, and representative of the great principle of animated existence, each of its sides referring to one of the three departments of creation, the animal, vegetable, and mineral.
The equilateral triangle is to be found scattered throughout the Masonic system. It forms in the Royal Arch the figure within which the jewels of the officers are suspended. It is in the ineffable degrees the sacred delta, everywhere presenting itself as the symbol of the Grand Architect of the Universe. In Ancient Craft Masonry, it is constantly exhibited as the element of important ceremonies. The seats of the principle officers are arranged in a triangular from, the three lesser lights have the same situation, the square and compass form, by their union on the greater light, two triangles meeting at their bases. In short, the equilateral triangle may be considered as one of the most constant forms of Masonic symbolism.
The right-angled triangle is another form of this figure which is deserving of attention. Among the Egyptians it was the symbol of universal nature; the base representing Osiris, or the male principle; the perpendicular, Isis, or the female principle; and the hypotenuse, Horus, their son, or the product of the male and female principle.
This symbol was received by Pythagoras from the Egyptians during his long sojourn in that country, and with it he also learned the peculiar property it possessed, namely, that the sum of the squares of the two shorter sides is equal to the square of the longest side - symbolically expressed by the formula, that the product of Osiris and Isis is Horus. This figure has been adopted in the third degree of Masonry, and will be there recognized as the forty-seventh problem of Euclid.Encyclopedia of Freemasonry
