Question

Which one of the following statements are true?

• A. If two angles form a linear pair, then each of these angles is of measure ${180}^{\circ }$.
• B. Angles forming a linear pair can both be acute angles.
• C. One of the angles forming a linear pair can be obtuse angle.
• D. The sum of the angles of a linear pair is ${180}^{\circ }$.

Answer 1

Answer: (C), (D)

The sum of the angles of a linear pair is ${180}^{\circ }$.

If two angles form a linear pair, either both of them are ${90}^{\circ }$ or one angle is acute and the other is obtuse. They cannot both be acute angles because in that case the sum would not be ${180}^{\circ }$ .