Helo on this question please

The hypotenuse of a 45 -45 -90 triangle measure 7 square root 2 units

Find the cosine function that is represented in the graph.

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.