Reuleaux Triangle

Couldn't find a decent 3D model of Reuleaux triangle (constant radius) available online, or others were modeled incorrectly. Decided to have a go myself. I believe this is a good challenge for modelers.
I will use this in a 2 part silicone mold to make plaster copies as inspired by http://fab.cba.mit.edu/classes/863.11/people/paulina.mustafa/02.html &
http://vloggest.com/watch/adam-savage-mini-science-fair-project-1070148843/
both of which I believe show incorrectly modeled triangles, which you can tell because the vertices should be indistinguishable however on those there is a clear bottom/top.