Question

How do you classify a angle?

Answer 1

Acute angle: measure between 0 degrees and 90 degrees
Right angle: measure is 90 degreas
Obtuse angle: measure between 90 degrees and 180 degrees
Straight angle: measure is 180 degrees

Answer 2

Well, you can classify all angle's by there, degrees, or there names, there are straight, right, acute or obtuse.
 straight is a 180 degree angle.  
right angle is a 90 degree angle 
acute is a angle less then 90 degree angle 
and obtuse, is a angle greater then 90 degrees but less then 180 degrees.
hope this helps