I can only assume your asking as you want to put a new badge in the exact origonal position.
Well, if you buy a genuine badge then they come with 2 prongs that go into the two holes in your bonnet, so positioning is done for you.
If you buy those stupid fake badges then yes you will need measurments. However i serious advise against it as ive gone down that route and the quality is absolutley shocking. Water seeps through etc etc. Pay the extra and buy genuine, trust me. Ive just recently bought two genuine badges.