Question

The supplementary angles which are in the ratio 5 : 4 are respectively ___.

• A. ${100}^{\circ },{80}^{\circ }$
• B. ${80}^{\circ },{100}^{\circ }$
• C. ${110}^{\circ },{70}^{\circ }$
• D. ${70}^{\circ },{110}^{\circ }$

Answer 1

The correct option is A

${100}^{\circ },{80}^{\circ }$

Let the angles be 5x° and 4x°.

5x° + 4x° = 180° ...... (given, the angles are supplementary)

9x° = 180°

x° = 20°

Therefore the angles are 5(20°) = 100 and 4(20°) = 80°

Verify your answer: 100° + 80° = 180° (The angles are supplementary)