Sorry if this doubles some other question, but I failed to find the right answer.
I am using LaTeX for writing math papers. However my knowledge of LaTeX and other computer programs is rather limited. In particular I have no experience at all in drawing figures. Now I am trying to figure out where to start learning this.
I have heard that there are programs allowing to create a figure and then encapsulate it into a LaTeX file. What are the user friendly programs of that kind? The type of figures I would like to create include knots, polytopes, convex bodies which I can easily draw by hand, but have no idea how to do it on a computer.
Given my modest background in computers, I would prefer something which is not very sophisticated and which could be learned and used relatively quickly. (I work with Windows, if it is important.)