Google Classroom구글 클래스룸
GeoGebra지오지브라 클래스룸

Construction #3

If there is a perpendicular bisector to a chord on a circle, the perpendicular bisector will go through the center of the circle. Someone could find the center of any circle by making two chords. Then they would find the perpendicular lines of both chords, and the center is where the who perpendicular lines intersect.