Let k be a circle with center M. There is another circle k1 whose center M1 lies on k, and we denote the line through M and M1 by g. Let T be a point on k1 and inside k. The tangent t to k1 at T intersects k in two points A and B. Denote the tangents (diifferent from t) to k1 passing through A and B by a and b, respectively. Prove that the lines a,b, and g are either concurrent or parallel. circlesconcurrentlinestangentgeometry