Like an angle between 90° and 180° (6)
I believe the answer is:
obtuse
(Other definitions for obtuse that I've seen before include "(Of angle) between 90° and 180° - dull" , "Blunt, not sharp or pointed" , "Blunt or unintelligent" , "To be thus blunt" , "Angle between 90 and 180 degrees" .)