Each health book is 3/4 inch thick. if mrs. meneses bookshelf is 2 feet wide, how many books can she fit on the shelf? explain to me how to do it

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.