Here is ax example of triangulation
t = (0:90:270)+45;
[x,y] = pol2cart(t*pi/180,1);
gd = [2;length(x);x(:);y(:)]; % geometry description
dl = decsg(gd); % decomposition
[p,e,t] = initmesh(dl); % initialize mesh (points,edges,triangles)
pdemesh(p,e,t)
help initmesh
What do you mean by curves inside?
I know only one way to generate non-obtuse triangle - just reduce size
To check angles of each triangles use dot product