Obtuse angles are over 90 degrees but less than 180 degrees. So minimum y can be is 10: (5 x 10) + 45 = 95 degrees (which is more than 90). Maximum for y is 26: (5 x 26) + 45 = 175 (which is less than 180 degrees)
The goal is not only to model the vector with 2 - D and to determine its important parameters, but also to examine the impact in the implementation. That is, Ogden's material parameters, element type, element size, and loading type.