CAN SOMEONE PLEASE HELP ME WITH THIS PLEASE!!

Which value of c would make he following expression completely factored? 8x+cy

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.

Need asap i will give brainliest and 98 points classify each pair of numbered angles corresponding, alternate interior, alternate exterior or none o these