Question

On rotating ray $OB$ in anti-clockwise direction, following figure is obtained.
Which of the following is/are true about the figure?

• A. $OA\&OB$ are arms of $\angle AOB$.
• B. $O$ is vertex of $\angle AOB$
• C. $\angle AOB=\angle BOA$

Answer 1

Answer: (A), (B), (C)

$\angle AOB=\angle BOA$

When two rays start from a common point then an angle is formed between the rays.
These two rays are called the arms of that angle.
The common start point is known as the Vertex of that angle.

Here, in the figure, arc is drawn for interior angle.
$\angle AOB=\angle BOA$
While representing an angle between two rays, vertex must be in middle.