Problem 466: Concentric Circles, Secant, Congruence, Measurement.
Level: High School, College, SAT Prep.
The figure shows two concentric circles and a secant ABCD. Prove that AB and CD are congruent.
Geometry problem solving
Geometry problem solving is one of the most challenging skills for students to learn. When a problem requires auxiliary construction, the difficulty of the problem increases drastically, perhaps because deciding which construction to make is an ill-structured problem. By “construction,” we mean adding geometric figures (points, lines, planes) to a problem figure that wasn’t mentioned as "given."