What is the first step when constructing an angle bisector using only a compass and a straightedge? a. place the compass needle on one of the legs of the angle, and draw an arc intersecting the other leg. b. mark a point outside the angle, and draw an arc centered at the point, intersecting the vertex of the angle. c. mark a point outside the angle, and draw a ray in any direction from the point. d. place the compass needle on the vertex of the angle, and draw an arc across both legs of the angle. e. mark a point in the angle's interior, and draw an arc centered at the point, intersecting both legs of the angle.