问题补充:
如图.△ABD和△ACE中,∠BAD=∠CAE=90°,AD=AB,AC=AE.(1)求证:△ABD全等于△ACE(2)试猜想:∠AFD和∠AFE的大小关系,说明理由人在 急
答案:
第一个应该是求证:△ABE全等于△ACD
1、证明∵∠BAD=∠CAE=90
∴∠CAD=∠CAB+∠BAD=∠CAB+90,∠BAE=∠CAB+∠CAE=∠CAB+90
∴∠CAD=∠BAE
∵AB=AD,AC=AE
∴△ABE全等于△ACD
2、∠AFD=∠AFE
证明:过点A作AM⊥CD于M,作AN⊥BE于N
∵△ABE全等于△ACD
∴S△ABE=S△ACD,BE=CD
∵AM⊥CD,AN⊥BE
∴S△ACD=CD*AM/2,S△ABE=BE*AN/2
∴CD*AM/2=BE*AN/2
∴AM=AN
∵AF=AF,AM⊥CD,AN⊥BE
∴△AMF全等于△ANF
∴∠AFD=∠AFE
======以下答案可供参考======
供参考答案1:
、证明∵∠BAD=∠CAE=90
∴∠CAD=∠CAB+∠BAD=∠CAB+90, ∠BAE=∠CAB+∠CAE=∠CAB+90
∴∠CAD=∠BAE
∵AB=AD,AC=AE
∴△ABE全等于△ACD
2、∠AFD=∠AFE
证明:过点A作AM⊥CD于M,作AN⊥BE于N
∵△ABE全等于△ACD
∴S△ABE=S△ACD,BE=CD
∵AM⊥CD,AN⊥BE
∴S△ACD=CD*AM/2,S△ABE=BE*AN/2
∴CD*AM/2=BE*AN/2
∴AM=AN
∵AF=AF,AM⊥CD,AN⊥BE
∴△AMF全等于△ANF
∴∠AFD=∠AFE
供参考答案2:
∠AFD=∠AFE.
理由:过A作AM⊥DC于M,AN⊥BE于N.
∵∠BAD=∠CAE=90°,
∴∠BAD+∠BAC=∠CAE+∠BAC,即∠DAC=∠BAE;