Deriving area of trapezium by using a parallelogram

Author:
Lew W. S.
In the three types of trapeziums shown below, the sides with length of a units and b units are parallel. The perpendicular distance between them is h units Use the "ship's steering wheel" and the "translate" slider to drag out a second trapezium and rearrange such that a larger parallelogram is formed from the two trapeziums ! Then, answer the questions below the diagrams.

Type 1

Type 2

Type 3

1. What is the area of the parallelogram formed from the 2 identical trapeziums ? (In terms of a, b and h)

2. What would be the area of one trapezium? (In terms of a, b and h)