Study the diagram, where points A, B, C, D, E, and F lie on circle Z.Line AB, segment DF, and segment C'E are drawn.Segments DF and CE intersect at point Z.Point G is on AB outside of circle Z.
Notice that segment GA is part of line AB that intersects the circle at points A and B, therefore AB is a secant. Segment GA is outside the circle, therefore, it is true that GA is an external part of a secant segment.
