Red Owl- not a dumb question at all.
Unless I missed it, no one has mentioned that it lso varies a lot depending on your style of rifle.
Just in case it is a Tennessee style rifle - on most upper East Tennessee rifles I have seen, they used double set triggers and they did not use tang bolts. The triggers were held in place by the triggerguard. They would cut a notch, or rather a little "step" in the forward end of the triggerplate, and the triggerplate was inlet flush with the wood so that the little notch at the front was slightly recessed below the surface of the wood. This formed a little ledge and the triggerguard (i.e. the 90-degree bend where the front of the bow meets the forward finial) rests on that ledge and holds the guard in. The triggerguard finials were usually inlet till the surface was just slightly proud of the wood, as the finial surfaces were often very slightly convex.
(PS You can still do this on most commercial triggers if want to use a tang bolt - there is usually room unless you are copying old original set triggers, like Myron Carlson did. Many of his triggers do not allow use of a tang bolt.)
If not a Tennessee rifle, this information is not so useful
, but the main point is, it varies a lot depenidng on the style of gun and type of triggers.
Guy