Question

is there a regular polygon with an interior angle sum of 9000° ?

Answer 1

exterior angles add to 360

interior angles are 180-exterior

so for an n sided polygon

ext = 360/n

sum of int = n* (180 -360/n)

= n (180n-360)/n

= 180n-360

so solve for n when sum = 9000

if it is an integer then there is such a polygon...