Met math photo challenge (a angle less than 90 digres)

This is a angle less than 90 digres because a angel les than 90 digres is a acute and this Pictor sows a acute not a obtuse or a right and you will youse this in the real world like if you are gowing too build a house you are gowing too know what angles are less then 90 digres more than 90 digres and just 90 digres.