You can't tell by the jaw line from the picture because the mouth is wide open. But there are a few things that suggest that this fish is a largemouth. The dorsal fins are nearly separate, there is no vertical barring above the lateral line, and there is no horizontal cheek barring present. There are other means of determining but they involve handling the fish and a dissecting scope to do scale counts and stuff. Imo, it's a largemouth.