○○○ψ ≈ 137.5°⪢⪢
As angles smaller than 180° proved to be more handy in practice, the smaller of the resultant angles is usually called golden angle. #math
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•Cross Product
Given two nonzero vectors in two or three dimensions, their cross product is a vector with magnitude equal to the product of the magnitudes of the vectors times the sine of the angle between the vectors and direction perpendicular to the vectors.
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