Which of the following will result in a rational number? Select all that apply. A. 645+9√4
B. 645−5√7
C. 645×9√4
D. 645÷5√7
help me please

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.