To determine the measurement of the second angle, we need to understand that supplementary angles are two angles whose measures add up to [tex]\(180^{\circ}\)[/tex]. Given that one of these angles measures [tex]\(60^{\circ}\)[/tex], we can calculate the other angle by following these steps:
1. Write the equation representing the sum of the two supplementary angles:
[tex]\[
\text{First angle} + \text{Second angle} = 180^{\circ}
\][/tex]
2. Substitute the given measure of the first angle into the equation:
[tex]\[
60^{\circ} + \text{Second angle} = 180^{\circ}
\][/tex]
3. To find the measure of the second angle, subtract [tex]\(60^{\circ}\)[/tex] from [tex]\(180^{\circ}\)[/tex]:
[tex]\[
\text{Second angle} = 180^{\circ} - 60^{\circ} = 120^{\circ}
\][/tex]
Therefore, the measurement of the second angle is [tex]\(120^{\circ}\)[/tex].
The best answer is:
A. [tex]\(120^{\circ}\)[/tex]
