Imagine a point inside a circle, close to the edge, and draw two lines to different points to the edge. That point isn't necessarily the center. Unless you add

Imagine a point inside a circle, close to the edge, and draw two lines to different points to the edge. That point isn't necessarily the center. Unless you add a third line of equal distance that needs to go to yet another point on the edge. The only way to make that work is if the point is in the center (and the lines automatically are radii).