You have asked good question about solidworks. I have no accurate answer of your question, but i have a you tube link of How to build a base flange through solidworks, If you interested to know about this, go through it: https://www.youtube.com/watch?v=7w4EPl2hQQI........... Hope this link help you..
Have a nice day......
Please find attached the Video Tutorial.
Answered with a tutorial: https://grabcad.com/tutorials/tutorial-how-to-model-a-base-in-solidworks