Question

如图,在三角形ABC中,AB=AC=12,BC=6,点D在BC上,点E在线段CD上,且角BEC=角ACB,BE延长线与A

Answer 1

（1）∵AB=AC,∴∠ABC=∠ACB,又∵BEC=∠ACB,∴∠BEC=∠ABC,∴∠BDE+∠DBE=∠BEC=∠ABC=∠DBE+∠CBE,∴∠BDE=∠CBE,∴△BCD∽△ECB,∴BD/EB=CD/CB,∴CD*BE=BD*BC(2)若AD=X,AF=Y,则BD=12-X,CF=12-Y,∵∠BDC=∠CBE,∠DB...