Task# Reflecting a rectangle over a diagonal

Illustrative MathematicsVaries

The goal of this task is to give students experience applying and reasoning about reflections of geometric figures using their growing understanding of the properties of rigid motions. In the case of reflecting a rectangle over a diagonal, the reflected image is still a rectangle and it shares two vertices with the original rectangle. The examples show that the reflected image looks like a rotation of the original rectangle about its center point. Moreover, this 'displacement' of the rectangle becomes smaller and smaller as the rectangle becomes closer to being a square.