如图,BE,CF是△ABC的角平分线,∠A=65°,那么BDC等于(  ) A.122.5° B.187.5° C.178.5° D.115°

问题描述:

如图,BE,CF是△ABC的角平分线,∠A=65°,那么BDC等于(  )
A. 122.5°
B. 187.5°
C. 178.5°
D. 115°

∠BDC=180°-(∠DBC+∠DCB),
=180°-

1
2
(∠ABC+∠ACB),
=180°-
1
2
(180°-∠A),
=90°+
1
2
∠A,
=122.5°.
故选A.