Could someone please help me with B. ? I think I got A. right, but I have no idea what to do for B. Who ever gets the question right first will be the Brainliest answer

In the following diagram it is given that dec,ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2

With finding limits of multi variable !

Over which interval is the graph of f(x) = x2 + 5x + 6 increasing?