Please help! geometry :/

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

Select a graph that have an equation with a < 0

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.