(1)因为△ABC是等腰三角形,AB⊥AC ,AD⊥BC
故:BD=AD=CD,∠B=∠DAF=∠C=45°,∠ADB=90°=∠ADE+∠BDE
因为DE⊥DF
故:∠EDF=90°=∠ADF+∠ADE
故:∠BDE=∠ADF
故:△BDE≌△ADF(ASA)
故:DE=DF,BE=AF
(2)因为BE=AF,BE=8 CF=6
故:AC=AB=AF+CF=14
故:BC=14√2
故:BD=1/2 BC=7√2
过E作EM⊥BC,M为垂足,因为BE=8,∠B =45°
故:BM=EM=4√2
故:DM=3√2
故:DE=DF=5√2
故:△DEF的面积S=1/2•DE•DF=25