Fill in the missing number. cm=1 meter

How to do this , and can some one explain

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.

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?