Cavalieri's Principle in 2D - Rectangle

Author:
epscholz
Dynamic illustration of a rectangle "sliced" into equally sized smaller rectangles. Student can choose height, width, number of parts and how far the slices move over.
Based on the animation of Cavalieri's Principle in 2D, what do you believe is Cavalieri's Principle? How can you illustrate the area formula for a parallelogram is height times width?