In how many ways can you fit all three pieces together to make shapes with line symmetry?

There are more than five solutions to this problem - how many can you find?
Can you find them all?
Additional printable copies of the shapes can be found here.
Try changing the question a bit:
For example, design your own set of three shapes (drawn on a square grid, as above), keep the total area 10. How many ways can they be arranged to make symmetrical shapes?
Can you find a set of three such shapes, which have more valid arrangements than the shapes from the original problem?
Can you find three such shapes which can never be arranged to make a symmetrical shape?