Malevich was a massively prolific painter, whose various styles I tried, for fun, to capture in this post, and I think I've failed. Honestly I'm sure there must be some Impressionist and Post-Impressionist pieces of his out there that I haven't found, not to mention a slew of other styles that he worked in that I might be neglecting–oh well!
Anyway, Malevich created a style known as Suprematism, which is founded upon the idea of using basic geometric shapes as the focus of a painting. His masterpiece in the style can be seen below, Black Square, which also at one dark time hung above his deathbed (or, rather, a version of it did). He described the creation of the Black Square thusly: "I felt only night within me and it was then that I conceived the new art, which I called Suprematism."
Knife Grinder (Principle of Flickering)
Oak and Dryads
The Female Bathers
Suprematism (Supremus 58)
Cow and Violin
River in the Forest
As an interesting–to me–aside, I believe there's an English translation of The Master and Margarita, by Mikhail Bulgakov, that uses the below painting, An Englishman in Moscow, on its cover.
An Englishman in Moscow