# Name of an angle between 0 and 180 degrees / $\pi$

Is there a name for and angle larger than 0 and smaller than $\pi$ or 180 degrees? So it covers acute, right and obtuse, it's kind of opposite of reflex angle. In my language there is a name for such an angle, so I'd be surprised if there isn't one in English. The term would then apply to every angle of a polygon iff that polygon is convex.

• Not sure how standard this is, but one source calls it a "convex angle." proofwiki.org/wiki/Definition:Convex_Angle – Thomas Andrews Jun 30 '16 at 19:23
• It may not be standard (I've never heard it, and I've been messing with geometry for a half-century), but if someone told me they had a "convex angle", I'd know that this was what they meant, so it seems like a pretty good term. :) – John Hughes Jun 30 '16 at 19:25
• Good question. But note, that some functions are defined for $\alpha \in [-\pi/2,\pi/2]$ – Yuriy S Jun 30 '16 at 19:26