Find the area of the triangle.

What is the difference between regular convex and concave polygons

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.

The sum of these consecutive integers is equal to 9 less than 4 times the least of the integer. find the three integers