I don really know why but it never made sense to me
An Isosceles triangle has two even parts, you add them up. For example 60 degree plus another 60 degree angle is 120 degrees. And the limit is 180 degrees, so in order to get that last angle, you'd have to subtract 160 from 180. And that'd be 20 degrees. I couldn't see the question but I hope this helps you in a way
It depends on the map. There should be a key indicated.
Answer:
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