幫幫手!!我唔識呀!!

ㄥB
= 180° - ㄥE - ㄥD
= 180° - 90° - 30°
= 60°ㄥFCB
= 180° - ㄥA - ㄥB
= 180° - 35° - 60°
= 85°

ㄥE=90゜(adjㄥ on st.line)
ㄥAFE+35゜+90゜=180゜(ㄥ sum of triangle)
ㄥAFE=55゜
ㄥCFD=55゜(vert .oppㄥ)
30゜+55゜+ㄥFCD=180゜(ㄥ sum of triangle)
ㄥFCD=95゜
ㄥFCB+95゜=180(adjㄥ on st.line)
ㄥFCB=85゜
有d複雜
希望幫到你la...=]

EBC+30+90=180(angle sum of tri)
EBC=60

60+35+FCB=180(angle sum of tri)
FCB=85

sol
to know that ㄥb=60゜(ㄥ sum of triangle)
so ㄥbca=85゜(ㄥsum of triangle)
so ㄥFCB=85゜

2010-11-30 19:58:04 補充：
http://img140.imageshack.us/img140/1255/screenhunter03nov300032.gif

http://img140.imageshack.us/img140/1255/screenhunter03nov300032.gif