Not entirely, you'll also need some kind of graphical library if you intend to have any visuals aside from text in a console window, but for now I wouldn't worry about that. And 3d is a whole different problem all together. Not your immediate concern, though :)

Later on you'll want to look into SDL as it might be a good step into graphics, but you seem to bite off more than you can chew with the learning process as your many (many) questions seem to indicate. For having just written a math problem solver and a hello world program, you shouldn't be concerned with the graphical side of things until you're more comfortable just tooling around in your language of choice.

I would relate you currently to a student who's just completed their first lecture in "intro to Biology" and is asking the professor about the finer points of brain surgery. You can be told specific answers, but you don't have enough under your belt to be able to do anything with the info. Relax and take the time to learn as you go :)

I don't mean to be rude, but you're starting to test people's patience with all the new threads. Genuine concerns are fine when your resources are exhausted, but Google and Wikipedia should be at the top of the agenda, when applicable.

Here's what Wikipedia has to say about SDKs.

Admiral