This week’s problem is similar to last week’s. Students’ development of mathematical reasoning involves making generalizations, and deeply felt generalizations are the result of making many specific observations (not just one)—and not merely reiterating the words that we or a book have pronounced. This week’s problem is intended to reinforce and extend the development of reasoning begun with last week’s problem.

Again, imagine that you had never heard of the Pythagorean Theorem (a2 + b2 = c2), and that you did not have a ruler. Using only the drawing below, determine the perimeter of triangle WKX. All corners that look square are square. The answer will be posted next week.