Trouble accessing public header

Im trying to make a plugin, and I have a public header file which needs to be accessed, from the private .cpp but it cant find it. Im all new to this and im sure its pretty easy to fix it, so im sorry for taking your time.

Private/RandomFile.cpp (trying to call a class from randomheader.h)
Private/PCH file which contains the randomheader.h

public/randomheader.h

shouldnt that work?