Google Classroom
GeoGebraGeoGebra Classroom

Will two suffice?

Instructions

Using the Algebra Pane on the left, click the circle to the left of one of the perpendicular bisectors to hide it. Did eliminating it change the location of the intersection of the other two perpendicular bisectors? Click the circle again to turn it back on. Now click the circle by a different perpendicular bisector to turn it off. Did that make a difference?