obtuseangle,acuteangle

types of angles: acute, obtuse, right
types of angles: acute, obtuse, right
锐角 acute angle 直角 right angle 钝角 obtuse angle
钝角(obtuse angle)大于 直角(90°)小于 平角(180°)的
common-pitfall-in-drawing-tetrahedral-obtuse-angle-between-wedge