This research was conducted among mathematics graduates who participated in a
pedagogical formation certificate program. Participants were asked to prepare a lesson
plan intended for use in teaching the Pythagorean theorem as part of a ninth grade
mathematics course. Eighteen out of 43 participants included a proof of the
Pythagorean theorem as a component of their lesson plan. These proofs were
classified in three categories: visual proofs (two participants), algebraic proofs (nine
participants), and proofs by using triangular similarities (seven participants). In
addition, the solved examples, homework, and evaluation questions included in the
lesson plans were classified according to TIMSS cognitive levels. Of the 233
questions prepared by 43 participants, 37% of the questions were at the knowledge
level, 60% were at the application level, and the remaining 3% were at the reasoning
level
