On weight: oblique cords and the axis of the force triangle
A straight cord bears all; the real and semi-real axes of the supporting triangles
Leonardo states that when a weight hangs from one straight and one oblique cord, the oblique cord bears no part of the load; but when two oblique cords share it, the loads stand in proportion to the obliquities and to the cords' lengths. He then defines two kinds of triangle axis: the "real axis," a perpendicular dropped from the real base between two right angles, and the "semi-real axis," which continues it in the same straight line. The worked figure shows triangle a b c with its real perpendicular d c and a partly dotted triangle f n t whose semi-real axis n o continues to o S. Diagrams include a suspended body (a c, b) and paired triangles (a d b, c).
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A straight cord bears all, an oblique cord none
If two cords suspend a weight and one is straight while the other is oblique, the oblique cord supports no part of the load. But if two oblique cords share a weight, the load divides between them in proportion to their obliquities.
Loads proportional to cord length
Of cords that descend from one same height with different obliquities to suspend a weight, the accidental weight joined to those cords stands in the same proportion as the lengths of the cords themselves.
Real and semi-real axes of the triangle
The triangle's axis is of two natures. The real axis is born from the real base between two right angles, as the perpendicular d c divides triangle a b c into a d c and b d c. The semi-real axis n o is born between two potential right angles f n o and t n o, and continues in the same straightness as the real axis to o S.