Gday mike & others you may also find this useful as a quick reference & a really good reference that I use myself & on teaching kids & covers most of the angles we shoot @
Now if @ all possible just look for the far leg as it gives you a idea of the angle the critter is on as on occasions a animal will be quartered more or less than we imagine/believe & then it's just put your cross hairs level with it vertically & centre of critter & squeeze off
It's extremely quick for reference & works on basically all critters ( a few exceptions & a few I don't know about )
Hope that makes sense
Cheers