In this math lesson, learners create parallelograms from square sheets of paper and connect them to form octagons. During the construction, learners consider angle measures, segment lengths, and areas in terms of the original square. At the end of the lesson, the octagon is transformed into a pinwheel, and learners discover a surprising result (the area of the octagon is equal to the area of the original square). This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.