A shop manual for your Corolla would tell you.
Crutchfield offers guides to all that sort of thing for free if you purchase something from them. I don't know about if you don't buy from them....
understand that these forums are focused on installing PCs in cars. There are better informational resources out there for car audio installs. There are certainly some knvery knowledgable car audio experts that peruse these forums, to be sure. however, there are more people with that level of knowledge on other forums that focus specifically on car audio.
Have you looked in the FAQ yet?
How about the Wiki?
Under normal circumstances, a signature would go here.