Shearing Intro
Shearing a figure preserves its area. Use the green rectangles to reason why parallelogram has the same area as parallelogram for any position of along that line, as long as , , and and are fixed.
What if you begin with a different parallelogram ?
How does the area of parallelogram compare to the sum of the areas of the green rectangles when or ? What about ? Explain.
What happens to the rectangles (and their areas) when is moved? Explain.