Using verticalregion for integral

I'm trying to plot the shaded region over which the integral extends, But i'm stuck.

F = @(x,y) y.*sqrt(x.^2 - y.^2);
ymax = @(x)x;
fcontour(F)

Answer 1

[Torsten]

x=[0 1 1];
y=[0 0 1];
fill(x,y,'b')