Using an external CA certificate

Hi List, Having a bit of trouble following the official freeradius wiki when it comes to certificates. Basically I have my own certificate which I want to use. I have a ***.crt file which was sent by my issuer, and a private.pem file which was created when I made my CSR request using openssl. I have uploaded the two files into my raddb/certs folder, but am unsure as to where to point to them in my eap.conf? I notice none of the cert files listed in eap.conf have a *.crt extension which is a bit confusing. Thanks in advance, Matt