PROPERTIES OF CIRCLES

c::J Open Investigation 7.'~ FINDING THE CENTER OF A CIRCLEBefore you begin the circle investigations you should take a supply of patty papers and construct alarge circle on each one. (A dozen will do.) Use a compass with a felt-tip pen or use a cup or glass as atemplate to make the circles.Step 1:Draw a circle on a patty paper. (If possible,do not use a compass.) See if you can discovera way to find the center of the circle by folding.Describe your method for finding the center of the circle.oStep 2:Step 3:Step 4:Step 5:Step 6:Step 7:Step 8:Take out another patty paper with a circle on it. Fold or draw two chords on your circle.Fold the perpendicular bisector of each chord.Use your compass to verify that the point of intersection of the perpendicular bisectors is thecenter of the circle.On another patty paper use your compass to draw an arc of a circle.Fold or draw two chords on your arc.Fold the perpendicular bisector of each chord, and mark the point of intersection of the twoperpendicular bisectors.Use your compass to verify that this point is the center of the circle that contains the arc youdrew in step 5.Use your results to write a conjecture about the point of intersection of the perpendicular bisectors oftwo different chords of a circle (or an arc of a circle).~44PROPERTIES Of CIRruS "5