Question

If a ray stands on a line, then the sum of the adjacent angles so formed is _____.

• A. 90°
• B. 100°
• C. 180°
• D. 360°

Answer 1

The correct option is C 180°


If a ray stands on a line, then the sum of the adjacent angles so formed is ${180}^{\circ }$.

We know that, angle on a straight line is ${180}^o$.
Here, the ray OB forms two adjacent angles $\angle COB$ and $\angle AOB$ on the line AC and hence $\angle COB+\angle AOB={180}^{\circ }$