Answer:
the correct answers are marked in green below
Explanation:
As with any right triangle, the length of the hypotenuse is equal to the root of the sum of the squares of the legs. That root is less than the sum of the leg lengths and greater than the longest leg (for non-zero leg lengths).
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Comment on the choices
The relationship is actually ...
║u+v║ ≤ ║u║ + ║v║
That makes the first selection possibly correct. It will only be correct if ║u║ or ║v║ is zero. The problem statement does not rule out that case.