Problem 555: Parallel lines, Angles, Sum
Level: High School, College, Math Education
The figure shows line L1 parallel to line L2 with angles a, x, y, and
z. Find x + y + z.
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."