Fill UV squares completely in all margin I try to UV in a cubic model using Blender (v2.79). 

I don't know how to do the same as this and must be like this:



The cubic model that I'm trying to UV like the previous even using Method: Angle-Based(These aren't the UV that I want):



What it should do?
To unwrap the UV, so that every Quad fills the UV space from (0, 0) to (1, 1), select the faces in the 3D View, press U and choose Reset from the unwrap dialog. (The bottom most option.)