Ratio between number of sides of two regular polygon = 1 : 2 ⇒ 1x : 2x Interior angle of the first Polygon = 120° Interior + Exterior = 180° I + E = 180° E = 180° - 20° = 60° Number of sides in the first Polygon =
360°
60°
= 6 side Number of sides 1x: 2x 6 :12 Number of sides in the second polygon = 12 sides Exterior angle =
360°
numberofsides
30° =
360°
12
= 30° Interior angle = 180° - Exterior angle = 180° - 30° Interior angle of the second polygon = 150°