Final answer:
In an indirect proof to show that angle X is a right angle, start by assuming the opposite, that angle X is not a right angle. This will lead to a contradiction using the Pythagorean theorem or trigonometric relationships, thus proving the original statement.
Step-by-step explanation:
When attempting an indirect proof (also known as proof by contradiction) to demonstrate that angle X is a right angle, you begin by assuming the opposite of what you are trying to prove. In this case, you assume that angle X is not a right angle. This assumption then leads to a logical contradiction when you use facts, definitions, and theorems such as the Pythagorean theorem or trigonometric relationships. By reaching a contradiction, you affirm the correctness of the original statement—that angle X is indeed a right angle.