Chris Wright contacted Sensei asking about the Triangle, Circle and Square philosophy.

Answer…

These three signs are symbolic of the breathing exercise of Koto Dama (literally, “word-spirit”, a Shinto practice based on the concept that certain sounds are imbued with, or help connect us with, the Universal Energy).

In the words of the Founder: When the Triangle, the Circle, and the Square become one, it moves in spherical rotation together with the flow of Ki, and the Aikido of Sumi-Kiri appears. We also relate each of these symbols to the basic principles behind all of the techniques in Aikido:
The Triangle, representing conflict, and the initial principle of getting off the line of attack.
The Circle, representing harmony; the circular, wave-like movements, which serve to blend our energy with that of our opponent.
The Square, representing resolution, good humour, and inner stability; the pin or throw which brings about a peaceful reconciliation with our partner.
The Japanese character embedded within the Triangle, Circle, and Square is the symbol for Ki (energy, life-force).
Below is a diagram of the Triangle, Circle and Square.