Question

Justin is constructing a line through point Q that is perpendicular to line n. He has already constructed the arcs shown.

A line n and an arc with center Q is drawn. Center Q lies above the line n. The arc cuts the line on two points A and B. A is left of B. Another arc is made with a center at A. The arc cut the line segment A B near point B. The arc is symmetric to line A B.

He places his compass on point B to construct an arc.

What must be true about the width of the compass opening when Justin draws the arc?

It must be the same as when he constructed the arc centered at point A