Aikido has a geometry of its own.
The power in the movement of Aikido comes from circular motion around a stable, energized center. Aikido is represented by the shapes of the triangle, circle and square. Some suggest that O'Sensei extracted these from Shinto cosmology and the theory of interconnectedness of matter and being.
One core shape of Aikido, the Circle, is present and apparent throughout the universe. Contemporary thinking is that this is the fundamental shape in sub-atomic particles. Ki is thought to flow into the body in a great spiral and radiates out similarly. Still, it must be remembered that Aikido is also based on the linear strikes of Japanese swordsmanship.
The Triangle can be said to represent the triangular posture predominant in Aikido, triangulation of arms to centre/hips, and triangular offline avoidance. The Square is about relationship to ukes ('attackers'); this can represent solidity of stance, or the principles of “being down-heavy."
The triangle also can be seenin the ideal stance or hanmi for stability -the feet in a close triangle. The close stance allows for speed and stability, and translates into "half-body." At a practical level the back foot is canted slightly to relieve any strain on the medial meniscus.
The alignment of the hips and the circular arcs of movement allow for the generation of significant power, like the winding and uncoiling of a spring.
Not all of Aikido may be explained by leverage or bio-mechanics. Over time, Ki energy combined with breath (kokyu) available to the aikidoka so that little tor no muscular resistance is needed to blend with the attack and execute a technique or throw.