First can you work out the formula for the area of a trapezium?[br]Rotate out a second trapezium for a clue.[br]Compare the shape to the formula for a parallelogram.[br]Check your answer with the "show area formula" box.[br][br]Second can you change the shape (using the 3 blue corner dots and the height dot) to make other shapes?[br]See if you can find a rhombus, parallelogram, rectangle, square and any tyoe of triangle.[br]How does the formula change for the different shapes? Look at the values for a and b on the shape and in the formula.[br]Use the rotate slider to see that it's still always a parallelogram.