Terrence is learning how to play the piano. Each lesson costs $18.50, and he usually pays for a whole month in advance. If he has 4 lessons scheduled for next month, how much will he pay?

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.