Question

初一数学求证题（2题,等腰三角形）

Answer 1

1.因为BD=AB,∴∠ADB=∠BAD.因为∠ADB+∠BAD=∠ABC,∴∠ABC=2∠ADB,又因为∠ABC=2∠ACB,∴∠ACB=∠ADB,所以AC=AD,∴2AB=AB+BD>AD=AC 2.因为AB+BD=DC,AB=EA,∴EB+BD=DC,即ED=DC,即点D是EC的中点又因为AD⊥BC,∴△AEC...