I'm having problems solving this proof. Two circles intersect at the points A and B, and through A, a secant is drawn intersecting the circles at the points C and D. Prove that the measure of the angle CBD is constant, i.e. it is the same for all such secants. When I draw it out on MS Publisher it looks like the measure of the angle CBD is truly the same. I measure the angles on the monitor, but I don't really understand why.
Bernie
Bernie