Given below is a trapezoid with bases *b*_{1} and *b*_{2} and height *h*. Move the slider to the extreme right and observe what happens.

Questions

- When alpha is 180 degrees, what shape is formed? Justify your answer.
- How is the area of the shape in 1 computed based on the figure?
- What is the relationship between the area of the shape in 1 and the area of the trapezoid?
- What formula will describe the area of the trapezoid based on the given above?