Which of the following demonstrates the correct first step in bisecting an angle?
create a point on the outside of the angle's rays.
draw a line that intersects one of the angle's rays.
place the compass on the vertex of the angle.
swing an arc that intersects one of the angle's rays.

Place the compass on the vertex of the angle.

Step-by-step explanation:

The following steps are used to bisect an angle.

1. Place the compass point on the vertex of the angle.

2. Spread the compass width to a length that stays on the angle or somewhere in the middle of both rays.

3. Draw an arc crossing both rays of the given angle. Now this arc makes two intersection points.

4. Place the compass tip on one of these new intersection points and spread the compass a bit more, and draw an arc in interior of the rays.

5. Without changing the settings of the compass, make an arc by placing the compass on the other intersection point.

6. Now join the vertex of the angle with the intersection point of the two small arcs.

This line divides the angle in two equal parts.

Hence, the answer here is - Place the compass on the vertex of the angle.