(i) Sum of angles of a regular polygon = (n-2) x 180°
= (9-2)x180° =7×180°=1260°
Each interior angle = Sum of interior angles/Number of sides =1260°/9=140°
Each exterior angle = 180°-140°=40°
(ii) Sum of exterior angles of a regular polygon = 360°
Each interior angle = Sum of interior angles/Number of sides = 360°/15=24°

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