It should be in your FCOM relating to the software version you have; but it used to be 45 degrees. If you were in a turn to an ATC intercept HDG and selected LNAV it would turn onto a 45 degree intercept. This was with software >2 years ago.
Thus you only selected LNAV when wings were level.
Likewise; if you selected a 'route offset' and selected LNAV it would turn onto a 45 degree intercept.
Last edited by RAT 5; 17th Nov 2016 at 21:09.