Mathematics, the great god of mathematics, come on! ! ! How to do 28 math problems in Shandong Taian 20 13 senior high school entrance examination? I was so worried.

Solution: (1)∵AB=AD CB=CD AC=AC.

∴⊿ABC≌⊿ADC

∴∠ BAC =∠∠ DAC ∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠∠87

∠∠AFB =∠ Conventional Armed Forces in Europe

∴∠AFD=∠CFE

(2)∵⊿ABC≌⊿ADC

∴∠ACB=∠ACD

∫AB∨CD

∴∠BAC=∠ACD

∴∠BAC=∠ACB

∴AB=CB

∴AB=CB=CD=AD

∴ The quadrilateral ABCD is a diamond.

(3) is the height of the diamond. Then point e is the desired point.

∫( 1)∠AFD =∠CFE

∠AFD+∠CFE+∠EFD= 180

∴2∠CFE+∠EFD= 180

diamond

∴∠CDA+∠BCD= 180

∠∠EFD =∠BCD

∴∠CDA=2∠CFE

In ∫ diamond ∠ FCE+∠ 1/2 ∠ CDA = 90.

∴∠FCE+∠CFE=90

∴∠CEB=90