If this is the dance position you are describing, then the arm and the leg of the dancer both make "right" angles (90º angles) to the floor.
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Answer:
HAVE YOU WATCHED OCTOPUS GAME
Step-by-step explanation:
You're trying to find constants

such that

. Equivalently, you're looking for the least-square solution to the following matrix equation.

To solve

, multiply both sides by the transpose of

, which introduces an invertible square matrix on the LHS.

Computing this, you'd find that

which means the first choice is correct.