Students will be able to use similar right triangles to prove the Pythagorean Theorem, and then work on identifying common student errors when using the theorem.

Students work on proving hypotheses – and end up proving the Pythagorean Theorem.

5 minutes

15 minutes

20 minutes

For our next activity, I give the class the Common Errors handout. I ask them to work in their groups, reviewing and correcting the work in the first part of the document.

5 minutes

To conclude this lesson, I ask the students to summarize the errors that they saw on the Common Errors handout (and any others they might have come across when using the Pythagorean Theorem!) I list their observations on the board.

Their homework is the final problem on the handout. The Homework_Problem asks students to prove a hypothesis about opposite sides of a quadrilateral.