Providing that it is a regular 15 sided polygon then each interior angle measures 156 degrees
Assuming that you do not mean a heavenly body, all that can be said is that the measure of one exterior angle of a polygon is 52 degrees: nothing more.
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a "regular" polygon
A regular polygon
An equilateral polygon
A regular 10 polygon
A regular polygon.
That would be a regular polygon.
Only if the polygon is "regular".
If the measure of an interior angle of a regular polygon is 140o, the polygon is a nonagon (sometimes called an ennagon) having 9 sides.
A regular polygon having an interior angle measure of 168o has 30 sides and is called a triacontagon.
Only when it is a regular polygon that all interior angles are of equal measure