Area of parallelograms - including a simple proof for the formula

Learn WHY the area of a parallelogram is calculated as base times height (altitude).

The formula is A = b x h and it is really simple to prove. If we cut a triangle off of one end of a parallelogram and move it to the other end, we get a RECTANGLE, whose area is the same as the based of the parallelogram times its height. So, it's really simple!

We also practice finding the areas of parallelograms, and draw a parallelogram with a given area.

This geometry lesson is meant for 6th grade, and is one in a series of lessons on area of polygons. Our next step is the area of right triangles, followed by the area of triangles.