[Gmsh] Stretched elements

[Agnese, Marco]

Hi,
I am trying to build a mesh with stretched elements along a direction but I do not know how to do that. 
To be more clear, let's suppose that I want to build a triangular mesh on a rectangle. 
I need that my elements are stretched along the x direction therefore the elements should look like  isosceles triangles with a small basis and very long edges. 
Is it possible to do that? How?

Thank you for your help,
cheers,
Marco.