# Constructing a circle

• Mar 3rd 2008, 06:43 PM
natester
Constructing a circle
Suppose A & B are points, and C is a circle whose center is A. Using only a straight edge and a compass whose setting does not survive lifting off of the page, construct a circle congruent to C centered at B.

Anything would help.
Thanks
• Mar 4th 2008, 03:55 AM
Opalg
Quote:

Originally Posted by natester
Suppose A & B are points, and C is a circle whose center is A. Using only a straight edge and a compass whose setting does not survive lifting off of the page, construct a circle congruent to C centered at B.

Anything would help.
Thanks

Step 1: You can construct the midpoint M of the line AB. (Draw a circle centred at A, passing through B. Draw a circle centred at B, passing through A. Draw the line connecting the two points where these circles intersect. This line meets AB at M.)

Step 2: Let D be one of the points where the circle C meets the line AB. Draw a circle centred at M, passing through the point D. Let E be the other point where this circle meets the line AB. Then BE=CD. So the circle centred at B, passing through E, is congruent to C.