I'd like to apply a fillet (rounding) of the corners of a triangle with selectable radius

Just as one can round the corners of a rectangle in Inkscape, I'd like to do the same with a triangle. Without affecting the curvature of the lines connecting the original tips. There is a way to move a node, but the range of curvature is limited. I'd like to have a box in which to choose the radius of the rounding, such as 0.25 inch or 0.5 inch etc.