Explain the Idea of Pangaea and how the continents have reached their current positions
It was almost certainly multiple.    I can't say for 100% but I think it was very very likely - cause of the way they split apart for one.

For example, today: Europe, Asia and in a practical sense, Africa are all connected but contain several different plates.    The Indian Plate and the Eurasian plate are 2 different plates but the land is connected, so you'd never know it was two plates - well, except for the frequent earthquakes.   



Source:  http://en.wikipedia.org/wiki/Indian_Plate

Plate Tectonics is thought to be about 3.2 billion years old:   http://sciencenordic.com/modern-plate-tectonics-arose-32-billion-years-ago