Finding the Center of A Circle
Posted By Larry Stroud on September 2, 2010
Thales Theorem is the basis for a simple method for locating the center of a circle using a carpenter’s square as follows:
1. Place the corner of the carpenter’s square anywhere on the circumference and position the “legs” of the square so they both intersect the circumference. Mark the points on the circumference where the legs intersect the circumference. Then draw a line connected the two marked points. This will be a diameter.
2. Repeat Step 1 but move the corner of the carpenter’s square to another point on the circumference.
3. The center of the circle will be located at the intersection of the two diameters.
This is illustrated in the following graphic:
