What is q equal to in the image above , first to answer for Q gets brainliest! URGENT

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- 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. 3- 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 part b?

Given: δabc, m∠1=m∠2, d∈ ac bd = dc m∠bdc = 100º find: m∠a m∠b, m∠c

What ratio is proportional to 18/21