Don't even bother to plug in that angle grinder. You don't need it and shouldn't use it.
Take the time to read some simple procedures and use the correct tools you already have that will do the job 100% better than an angle grinder.
Go to this site and read:
Click here for link to "Cutting a tenon on a timber" list of procedures with photos. Then ask some more question before you pick up a tool like an angle grinder, to use it to cut wood.
Jim Rogers