A student thought she had 3 missing assignments, she actually had 5 missing assignments. What was her percent error?

If the measure of xyz is 81 what is the measure of yz

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.

Asap! i'm not good math and i'm lost.