Hi…
I use DevC++ compiler but always that I try to compile some program it send a messages like that below for all GL/glut.h functions:
[Linker error] undefined reference to `glBegin@4’
Can somebody help me?
Have you linked the correctly on your project ?
usually, the external symbol errors means it’s a problem from linking
I use another compiler so I can’t telling you the correct manipulation, try to find with any tutorial 
If this problem persist, display your code here plz
I believe you are using a vc++ library, usualy with .lib extension, devc++ uses mingw and you need the apropriate library, in this case .a. I can’t remember where i found it but if you send an email to uber_napalm_cobra@hotmail.com ill send it back to you, otherwise if you don’t want to give your email out just try searching for opengl+mingw.
Add the file libglut.a to your project, Its in the DevC++ Lib folder.
Btw that header does not exist in DevC++, Try the .a libary.