Question

Assertion : Sum of the pair of angles (like ${120}^{\circ },{60}^{\circ }$ ) is supplementary.
Reason : Two angles, the sum of whose measures is $180°$, are called supplementary angles.
Which of the following is correct.

• A. If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
• B. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
• C. If Assertion is correct but Reason is incorrect.
• D. If Assertion is incorrect but Reason is correct.

Answer 1

The correct option is A

If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

Explanation for the correct option:

Determining the correct statement:

Sum of the pair of angles like ${120}^{\circ },{60}^{\circ }$ is supplementary.
As we know that two angles are said to be supplementary if the sum of the angles$=180°$

$\because {120}^{\circ }+{60}^{\circ }={180}^{\circ }$

Therefore, the assertion is true.

Two angles, the sum of whose measures is $180°$ are called supplementary angles.
Therefore, the reason is true

Thus, both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

Hence, option (A) is the correct answer.