How to Center Circle Without Using Tools?

An experiment can be performed to determine the center of the circle without using special tools. It need not even use the term as usually draw a circle, but simply use any flat object that has a right angle that are around you. For example paper. Here's how determining the center of the circle, the first paint-diameter diameter, and then determines the intersection of the second diameter.
Put a mark on the perimeter of a circle using a piece of paper that have square corners.
Its diameters can be obtained (as shown). Diameter BC and FG.
Two diameter it would intersect at one point. That point is the center of the circle we were looking for (in the picture is the point P).
Explanation technique: If two bowstring meet at a point on the circumference of a circle, and two chords that form a right angle at the point before, then the line in front of the right angle it must line straightener () is none other than the diameter of the circle. When two diameters intersect, the intersection that was the center of the circle
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