Find the measure of the arc or angle indicated.
GEOMETRY
Thank you!

Anyone know? will mark brainliest if you're correct!

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

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?