Triangle: gas, air, beginning, creation, procreation, ryutai, inhalation, yin, man.
Circle: liquid, water, implementation, development, Jutai, apnea, yin / yang, heaven.
Square: mineral, rock, finally Gotai, exhalation, yang, earth.
The list is endless, these are just some examples of the rule of "triplicity" or Sangen.
O'Sensei said: "Enter as a triangle, run as a circle and a square end."
The following article was published in Black Belt magazine No. 10
"Morihei Ueshiba O'Sensei sometimes resorted to images of the triangle, circle and square to illustrate concepts related to movements and moments of Aikido. Starting from point and line, have not yet surface, these are the basic shapes of geometry that when volume is added, become bodies pyramid, sphere and cube. imagery that speaks the Master are the product of his effort to transmit his thoughts synthesis and requires of us, at the same time, an equivalent effort to uncover its meaning. This is not a purpose but purely intellectual encyclopedic or track to guide our practice toward improving our technique, which in turn will lead us to rediscover from there, with our own seal, the teachings of Aikido.
So the triangle symbolizes the momentum, the onset of movement, energy projection. The circle refers to movement continuity, to infinity. The square represents the static, the solid, the stable, the material.
's Own posture triangular Kamae (guard), provides stability while the possibility of moving in all directions, either forward, backward, rotating redeploying hip without moving the feet (Tenkai) or moving back forward or backward (Tenkan). Tetrahedron or pyramid provides us keys for movement in four, and eight directions.
The circle is the distinctive figure of Aikido, either ovals, slings or spiral, the circle is always present and the more perfect execution, the better the technique. The circular movement lacks edges, interruptions. The energy flows freely along a path clear. But sometimes pursue the circle only through the circumference and forget his other two major components: the radius and the center. Without the presence of these two elements melts circumference. The radius is the penetration road to occupy the center. The radius is a line to the center and it should be the input (Irimi) directly, determined. And a firm center body movement (tai sabaki). The imbalance and projection come as a natural consequence of this movement.
The square is formed in the retention, with its base firmly on the floor, the lines of force of the diagonals cutting the Uke and weight down its edges as the Law of Gravity. These three geometric representations have many other implications: physical, esoteric ideals and also beyond the scope of this paper and many of them and know the author of this note. "