Answer:
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Step-by-step explanation:
If you get a normal ruler it will be one foot total. You add the bigger measurements twice because they're an inch. Then you add half of those measures. It will be numbered 1, 2, 3... so on . In other words, the longer lines are inches and the shorter ones are centimeters.
-6(12)= -36
(13)(-3)= -39
(-5)(16)= -80
N = 30 makes that a perfect square