Answer:
If the lines that forms < X are perpendicular, it can be assumed that it is a right angle.
Step-by-step explanation:
An indirect proof of an angle is an assumption about the value of the angle that can be made by mere inspection and some considerations.
< X = right angle = [tex]90^{o}[/tex]
A right angle is one that is equal to [tex]90^{o}[/tex]. As an indirect proof, if the lines that forms the angle are perpendicular; then it can be assumed to be a right angle. Because perpendicular lines are at right angle to one another.