Set the height of parallelogram ABCD to 6 and the length of the base to 8. Then click "Move triangle" button to move triangle ABE. What is the shape now?
What are the width and height of the rectangle?
Write an exptression for the area of this rectangle.
What is the area of the original parallelogram?
What do you think is the formula for area of parallelogram (please express in terms of its height and base)?
Try to change the height and base of the parallelogram and move the triangular segment to calculate the area.