How did Pangea form and how did it break-up?

Pangea formed when the continental plates, which make up the earth's surface, collided.  It broke up when they floated apart.

i dont know how it formed but it seperated because of tectonic plates or something like that. anyways they are constantly moving together, apart, or overlapping. thats why there are mountains, oceans between north america and europe and also why cali and florida are sinking.

Formation was due to the magnetic pull of the earth (south) . Then about 220 m.y.o the continents began to split apart because the pull changed to the north. Causing the continents and Rift zones to slowly drift, collide against each other, subduct, slide apart  (such as the San Andreas Fault in Calif.) They are still moving today as much as 4 cm. in places.

The Earth's crust  is made up of a bunch of tectonic plates that are constantly moving.  The continental crust sometimes collides with another continental crust.  An example is India, that was part of African plate but  many millions years ago this plate was divided. India become a big island, moves to the north and then collided to Asia plate.  See that the plates' tectonic changes the shape and location of the continents.
There are two different types of crust: the first, that contain basaltic rocks, more dense, forming the ocean bottoms, and the second of granitic rocks, forming continents and swallows seas.

A plate (and the continents in that plate) can divide in two or more plates. A basaltic plate can disappear when collides with a granitic crust, but if the plate have granitic crust and collides with another similar plate, the granitic crust will form ranges like the Himalayan. The old ranges far from coast lines (Urals, Appalachian) was form due to plate collisions.    There was a time after many collisions, when almost the lands was together (a super-continent), but this plate divides again in different new smaller plates.