What is a simple method to locate the center of a circle on a sketch or piece of material?

What is a simple method to locate the center of a circle on a sketch or piece of material?

• A. draw a diameter across the circle
• B. draw two nonparallel chord lines across the circle and then a corresponding perpendicular bisector line across each chord line
• C. fold the circle along its diameter
• D. connect the circle's extreme points with a straight line

Answer: (B)

The center of a circle lies on the perpendicular bisector of every chord, so you can locate it by intersecting two such lines. Start by drawing two chords that aren’t parallel. Then construct the line that is perpendicular to each chord at its midpoint. The point where these two perpendicular bisectors cross is the circle’s center. This works because each perpendicular bisector passes through the center, so their intersection pinpoints the exact center. This method is reliable on rough sketches since it relies on basic straightedge work and a clear geometric fact, without needing to eyeball a diameter or rely on folding or connecting boundary points.

The center of a circle lies on the perpendicular bisector of every chord, so you can locate it by intersecting two such lines. Start by drawing two chords that aren’t parallel. Then construct the line that is perpendicular to each chord at its midpoint. The point where these two perpendicular bisectors cross is the circle’s center. This works because each perpendicular bisector passes through the center, so their intersection pinpoints the exact center. This method is reliable on rough sketches since it relies on basic straightedge work and a clear geometric fact, without needing to eyeball a diameter or rely on folding or connecting boundary points.