Question

19数学题求解答

Answer 1

Answer 2

∵∠ABC=∠ACB
∴AB=AC
∵AD⊥CD,AE⊥BE
∴∠ADC=∠AEB=90°
∵AC=AB,AD=AE
∴RT△ACD≌RT△ABE(HL)
∴∠CAD=∠BAE
∴∠CAD-∠DAE=∠BAE-∠DAE
即∠2=∠1
2. ∵△ACD≌△ABE
∴∠ACD=∠ABE
∵∠ACB=∠ABC
∴∠ACB-∠ACD=∠ABC-∠ABE∠
即∠BCD=∠CBD
∴OB=OC

Answer 3

1、∵∠ABC=∠ACB，那么AB=AC
AD=AE，AD⊥CD，AE⊥BE
∴RT△ACD≌RT△ABE(HL)
∴∠CAD=∠BAE，那么∠1+∠DAE=∠2+∠ADE
∴∠1=∠2
2、RT△ACD≌RT△ABE(HL)
∴∠ACD=∠ABE
那么∠ABC-∠ABE=∠ACB-∠ACD
∴∠CBO=∠BCO
∴OB=OC

Answer 4

Answer 5

Answer 6