Center drill holes on or in a triangle?

[Woodpecker]

Help. I have a project with a 5.5" circle and need 3 ea 1/4" hole at the vertex of the triangle of 4.25".
The angles equal 60 degrees and I don't know if there is a button to push and confirm the 1/4" drill holes to be exact on the triangle
vertex 3 Points. The drawing is a scan from the CW. This the best available at this time.
I have no idea why I am doing this, it is one old hour glass with wood and I want to cut new top and base then replace with three brass rods using brass cap nuts. When done a photo will follow. Woodpecker