Assuming that the angle is shown and the degrees is explicitly shown, then you can conclude the following:
If the angle >= 0 and the angle < 90, then the angle is an acute angle.
If the angle = 90, then the angle is a right angle.
If the angle > 90 and the angle <180, then the angle is an obtuse angle.
If the angle = 180, then the angle is a straight angle.
