a) In the image, we know that ABCD is a parallelogram and that means opposite angel measures should be the same. We know that angel DCB is made up by angel 1 and 2, and angel DAB and DCB are equal and angel DAB is made up by angel 1 and <em>x</em>. So now we can conclude that angel <em>x</em> is equal to angel 2.
b) According to the definitions of a parallelogram, opposite angel measures have to be the same, while AECF have angle 1 to angel 1 and angel 2 to angel 1. We can conclude that AECF is <u>NOT</u> a parallelogram. (Sorry, you didn't give me the full question so some information remains unclear. )
Quadratic equations always have a degree of 2. That means that we will always have an x² term. Of the 4 choices, only A and B offer a term of x², making them a quadratic.
