A man mowing his four-sided yard is unable to remember all of its dimensions. He remembers that one corner is 85°, another is 70°, and another is 105°. What is the measure of the fourth corner?

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?