Question 983960
I worked this one.
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The other tutor gave answers of 9 and 16.
Both satisfy the equation, but 16 sides gives one angle that is 180 degs, then some that are greater than 180.
An angle of 180 doesn't count as an angle.
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--> only the 9 sides solution works.
120 + 125 + 130 + 135 + 140 + 145 + 150 + 155 + 160 = 1260 --> 9 sides
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for 16 sides,
+ 165 + 170 + 175 + 180 ...  That's NG.