A car dealership has piled up a huge inventory of cars with the hope that it can supply more cars and make a massive profit even for a small rise in car price. The supply curve representing the supply for the dealership is

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.