What is the sign of − x y

Which is a true statement about an exterior angle of a triangle a. it is formed by two segments that are not sides of the triangle, b. it forms a linear pair with one of the interior angles of the triangle, c. it is complementary to one of the interior angles of the triangle. d. it is formed by two segments that are sides of the triangle.

We just started the introduction into circles and i have no idea how to do this.

Wich statement could be used to explain why the function h(x)= x^3 has an inverse relation that is also a function