If two equal chords of a circle intersect each other, show that two segments of one are equal to two segments of the other.

Problem: A chord AB one of the two concentric circles intersect the other circle at points C and D. Prove that AC = BD. General enunciation: A chord AB one of the two concentric circles intersect the other circle at points C and D. We have to prove that AC = BD. Particular enunciation: Let ...