4c-7.8 evaluate the expression if c=4

Aportion of a line bounded by two points is defined as

The diameter of a circular chip is doubled to use in a new board game. the area of the new chip will be

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.