求:已知∠BAC为钝角,AB=AC,BE=CD求证∠ADC=∠AEB

、已知CD⊥AB,BE⊥AC,OB=OC.求证 AO平分∠BAC 已知:如图,点E在AC上,AB平行于CD,∠B=∠AEB,∠D=∠CED.求证:BE⊥ED 如图，已知：点E在AC上，AB∥CD，∠B=∠AEB，∠D=∠CED．求证：BE⊥ED． 已知如图,点E在AC上,AB平行CD,∠B=∠AEB,∠D=∠CED,求证BE垂直ED 如图所示,已知AB=AD,CB=CD,E是AC上一点,求证：∠AEB=∠AED 如图,BE与CD相交于点O.已知AD=AE,∠ADC=∠AEB. 已知CD⊥AB于点D,BE⊥AC于点E,BE、CD交于点O且AO平分∠BAC,求证；OB=OC 在四边形ABCD中,AB‖CD,AB⊥CD,∠AEB=∠CED.F为BC的中点,求证AF=DF=0.5（BE+CE) 己知如图点E在AC上AB∥CD.∠B=∠AEB.∠D=∠CED,求证BE∥ED 如图5-18,已知AB=AD,CB=CD,E是AC上一点,求证:∠AEB=∠AED 图,已知BE和CD相交于点O,AO平分∠BAC,AB=AC. 如图,已知AB=AC,CD⊥AB于点D,BE⊥AC于点E,BE,CD交于点F,求证AF平分∠BAC.