How to use earlier part as a reference?

Hello everybody! I'm new in SolidWorks and I have a question.

I modelled part A. I saved it and now I want to draw part B. If i use "new part" I can't use part A as my reference. Or can I? How to use part A as my reference? Any tutorials? I don't like to remember all the dimensions from part A or create a drawing to get correct dimensions.

I want to make assembly with these two parts...

I wish you understood my English

Henri

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