The figure below shows a quadrilateral ABCD
with angle BAD = 90 degrees, angle ACB = 30 degrees, angle ADB = angle
BDC = x, and angle CBD = 2x. If angle BCD is obtuse, find x.
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 illstructured problem. By
“construction,” we mean adding geometric figures (points, lines,
planes) to a problem figure that wasn’t mentioned as "given."
