Answer:
Yes, it is. Functions can only have one output (y) for each input (x). Furthermore, this means each x value will only have one y passing through it. Thus if we plot it on a graph and it passes through a horizontal line more than once, it is not a function. This is called the vertical line test.
All of the angles added together MUST equal 180 degrees, so take 180 and subtract 84 from it.
Therefore, the third angle is a 96 degree angle.
