Question

How can a parallelogram be cut and rearranged to show that the area of a parallelogram can be calculated using "A=bh", the same formula used when calculating the area of a rectangle?

Answer 1

I have attached an image that hopefully will be helpful for you.
Step 1: draw a line from one of the vertices so it intersects the opposite side at a right angle (this is called the height). you have just divided the parallelogram into a triangle and a trapezoid.
Step 2: place the triangle you created over on the right side of the newly created trapezoid. this will create a rectangle, whose length is the same as the base of the parallelogram, and whose width is the height of the parallelogram.
hope this helps.

Answer 2

If you cut it at the bottom to the top to make right angles at the top and bottom then move the triangle you just made to the other slanted side then it will form a rectangle with the same base and height as the parallelogram.