The answer to this is Hexagon.
For any polygon the sum of the exterior angles is 360. Since The polygon is regular divide 360 by 12 to get the exterior angle measure. Interior and exterior angles are supplemental so subtract the exterior angle measure from 180.<span>
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Sub in the numbers
2(5)^2 - 4(5) + 5
=50 - 20 + 5
=30 + 5
=35
Day 1: 8km=4.97miles
Day 2: 10miles=16.09km
Day 3: 9miles=14.4km
9.6km=5.9miles
I really hope this helps! Not really sure what exactly the answer you are looking for is but this should help you figure it out