Select the statement that correctly describes acute angles and obtuse angles.
An acute angle is equal to 90°, and an obtuse angle is greater than 90°.
An acute angle is less than 90°, and an obtuse angle is equal to 90°.
An obtuse angle is greater than 90°, and an acute angle is less than 90°.
An obtuse angle is equal to 90°, and an acute angle is less than 90°.