What are the coordinates of the undefined vertex in the parallelogram below

Prove conjectures

Geometry is the part of mathematics that deals with the relationships between lines, angles and surfaces. On the other hand, deductive rules refers to argument forms where true premises result in a conclusion that must be true and are called valid arguments. Deductive arguments that are not in a valid form are called invalid arguments. What is important here is that If I assume the premises are true, is it possible that the conclusion could be false?  If the answer "yes" then the argument is invalid and valid if you answer "no".

So, we can use deductive rules to prove conjectures. A conjecture is a theory based on information that is not complete. Thus, we can use the question If I assume the premises are true, is it possible that the conclusion could be false? to get valid or invalid arguments.