## Applications of Geometry

July 1, 2010This is a problem that has occurred to me as I have been working on tables for my classroom. I have worked out a more mundane solution, but I think it’s still an interesting problem:

I have a circle that’s approximately 48″ in diameter and I need to find the center point. How do you locate the center of a circle?

The method I worked out in my head (I haven’t tested it yet), is to mark a beginning point on the edge of the circle and measure the circumference. Half of that should be a semicircle, which is formed by a diameter. Draw the diameter (or at least a portion of it). Move the beginning point, measure another semicircle, and draw another diameter. The two diameters should cross at the center of the circle.

(The method I will actually use is to transfer the quarter-circle markings from the underside of the circle to the top, but I think I will also try the other method as a test.)