Answer:
1260°
Explanation:
Number of sides was given as 9, hence ( n= 9)
Sum of interior angle of a polygon can be determined using the expression below
[(2n-4)90°]
Substitute n=9
[((2×9) -4)) ×90]
= [(18-4)×90]
(14×90)=1260°
Hence, angle sum of polygon which had 9 sides is 1260°