# Finding the center of a circle with any right angled object

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1.  Place the right-angle corner of any object at any point on the circle. Any point will do.
2.  Make a mark where the two sides of the right-angle cross the circle.
3.  Draw a line between these two marks. Because of Thales Theorem, this is a diameter of the circle.
4.  Place the right-angle corner of the object at any other point on the circle. Any point will do, but for greatest accuracy, make it about a quarter the way round the circle from the first point.
5.  Make a mark where the two sides of the right-angle cross the circle.
6.  Connect these two points with a straight line. This is the second diameter.
7.  Done. The point where the two diameters intersect is the center of the circle.
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