Just refreshing your knowledge on basic mathematics

    
                                     Different Angles have different names:
      

An acute angle is less than 90 degrees

Also: the letter "A" has an acute angle.

Which Angle?

n

Remember to look carefully at which angle you are being asked to name:

The acute angle is the small angle which is less than 90°.

If you choose the larger angle you will have a Reflex Angle instead:
	The smaller angle is an Acute Angle, but the larger angle is a Reflex Angle