A few beveling tips to keep in mind. Looking for Blender 3d resources? Check out my website for links to assets, addons, discord, and more. www.pzthree.com/
Hi, about that triangular object. What you need is a circle tangential to triangle sides (or any arbitrary shape). The simplest method is to make an inset face, where inset is equal to circle (thus bevel) radius. Then just place circles centers at corners of that new face and you're done.