Question

If an angle is 60° less than two times of its supplement, then the greater angle is ______.

Options

• 100°

• 80°

• 60°

• 120°

Answer 1

If an angle is 60° less than two times of its supplement, then the greater angle is 100°.

Explanation:

Let an angle be x.

∴ Its supplement = 180° – x

According to the question,

x = 2(180° – x) – 60°

⇒ x = 360° – 2x – 60°

⇒ x + 2x = 300°

⇒ 3x = 300°

⇒ x = `300^circ/3` = 100°

And its supplement = 180° – x

= 180° – 100° 

= 80°

Thus, the greater angle is 100°.