Let's make a sample delaunayTriangulation and plot it.
x = rand(20,1);
y = rand(20,1);
dt = delaunayTriangulation(x,y);
triplot(dt);
Create an array of labels for the points. I'm just using the indices of each point, but if your points have some meaning (cities, for example) you could build your vector of labels taking advantage of that information.
labels = string(1:numel(x))
Add the labels to the plot. If you wanted to be fancier you could add a slight offset to the x and/or y coordinates so the text appears a little bit further away from the point to which they correspond.
text(x, y, labels)
Let's spot check. Does the code below circle point 15?
hold on
plot(x(15), y(15), 'ro', 'MarkerSize', 20)
