What is the negation of this statement A is a right angle?

The negation of the statement "A is a right angle" is "A is not a right angle." This means that angle A could be either an acute angle (less than 90 degrees) or an obtuse angle (more than 90 degrees), or it could be a straight angle (exactly 180 degrees) or even a reflex angle (greater than 180 degrees). Essentially, the negation covers all possible angles that are not right angles.