Marcello is constructing the perpendicular bisector of ab¯¯¯¯¯. he has already constructed arcs as shown. what should marcello do for his next step? a) place the point of the compass on point x and draw an arc, using ay as the width for the opening of the compass. b) use the straightedge to draw a line through points x and y. c) use the straightedge to draw ax←→ and ay←→. d) place the point of the compass on point x and draw an arc, using ax as the width for the opening of the compass.