Q21 of 113 Page 128

If two supplementary angles are in the ratio 1 : 2, then the bigger angle is

Ratio = 1 : 2


Let the angles be x and 2x


Sum of supplementary angles is 180°


x + 2x = 180°


⇒ 3x = 180°


⇒ x = 60°


The bigger angle = 2 × 60° = 120°

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