Why is the product of a rational number and an irrational number irrational

Me! #1 write an equation for the interior angles of this triangle that uses the triangle sum theorem. #2 what is the value of x? #3 what is the measure of #4 classify the triangle above as acute, obtuse, or right. state your reason in a complete sentence.

If square root x = -7, then x= -49 true or false

He that is measured at 220° is a reflex angle. the opposite angle is obtuse. find the measure of obtuse .