What is one reason that Africa has such varied geography?

The movement of tectonic plates is a major cause of the varied geography of Africa.

Explanation:

Africa is the second largest continent in the world, and of course its geography is not monotonous but very interesting and varies from one part to another. There are multiple reasons as to why the geography of Africa is varied and one of the major one is the movement of the tectonic plates.

The continent has a large plateau in its central part, remnant of one of the oldest landmasses in existence and once part of a major mountain forming processes. The northwestern part has mountains formed because of the complex convergent boundary with Eurasia. The southern part of the continent too is mostly a plateau which is remnant of ancient tectonic activity that created mountain chains.

The eastern part of the continent has lot of volcanic activity, a high plateau, and an ever growing rift valley. This is due to the current tectonic activities as in this part there is  divergent plate boundary that separates the continent into two plates, causing lot of volcanic activity and creating a gap between the two plates. The plateau has formed at the start of this process when the crust was pushed up before it cracked and started to split.