Problem 301: Tangents to a circle, Secants, Major Arc.
Level: High School, College, SAT Prep.
In the figure, AB and AC are tangent to circle O at B and C,
respectively, and D is a point on the major arc BC. Lines BD and AC meet
at E, and lines DC and BA meet at F. If
BF = a, CE = b, and EF = x, prove that