The proof questions in junior two mathematics can comprehensively reflect students' ability to analyze and solve problems. What are the proof questions in junior two mathematics? Next, I will bring you the D proof of the second grade mathematics for your reference. Senior two math proof questions 1, as shown in the figure, AB=AC,? BAC=90？ ，BD？ AE, CE in d AE is in e. and BD & gtCE, which proves that BD=EC+ED. Answer: Proof: ∵? BAC=90？ ，CE？ AE，BD？ AE，ABD+？ Bad =90? ,? Bad+? DAC=90？ ,? ADB=？ AEC=90？ . ABD=？ DAC。 Again ∵AB=AC, (? △ABD?△CAE(AAS)。 ? BD=AE，EC=AD。 ∫AE = AD+DE，？ BD=EC+ED。 2 and △ABC are equilateral triangles. ? ACB=90？ , AD is the center line on the side of BC, the vertical line passing through C is AD, the point passing through AB is E, and the point passing through AD is F. Verify? ADC=？ BDE solution: as CH? AB in H and AD in P, ∫ AC = CB△ABC in RT,? ACB=90？ ，CAB=？ CBA=45？ . HCB=90？ -? CBA=45？ =? CBA。 Again ∵ midpoint d,? CD=BD。 CH again? AB，？ CH=AH=BH。 Again? PAH+？ APH=90？ ,? PCF+？ CPF=90？ ,? APH=？ CPF，PAH=？ PCF。 Again? APH=？ CEH, in △APH and △CEH? PAH=？ ECH, ah =CH,? PHA=？ EHC？ △APH?△CEH(ASA)。 ? PH=EH, and ∵PC=CH-PH, BE=BH-HE,? CP=EB。 In △PDC and △EDB, PC=EB,? PCD=？ EBD，DC=DB，？ △PDC?△EDB(SAS)。 ADC=？ BDE。 2 proof: OE? AB, OF in e? AC in f? 3=? 4, ? OE=OF。 (Here comes the question. What is the reason? I'm a little confused. 1=? 2, ? OB=OC。 ? Rt△OBE≌Rt△OCF(HL)。 5=? 6. 1+? 5=? 2+? 6. namely. ABC=？ ACB。 ? AB=AC。 ? △ABC is the intersection o of isosceles triangle and OD? AB versus D, O, OE? If AC proves that Rt△AOD≌ Rt△AOE(AAS) is in E and OD=OE, can Rt△DOB≌ Rt△EOC(HL) be proved again? ABO=？ ACO, again? OBC=？ OCB, do you understand? ABC=？ ABC gets isosceles △ABC 4. 1. E is a point of ray AB, and square ABCD and square DEFG have a common vertex D. When E is in motion,? Is the size of FBH a fixed value? And verify (f is FM? AH is in m, and △ADE is equal to △MEF. ) 2. Triangle ABC with AB and AC as sides makes square ABMN and square ACPQ 1) If DE? BC, prove: E is the midpoint of NQ 2) If D is the midpoint of BC,? BAC=90？ , verification: AE? NQ 3) If f is the midpoint of MP, FG? BC in g, verification: 2FG=BC 3. It is known that AD is the height on the edge of BC, and BE is? The bisector of ABC, EF? Proof of BC, AD and BE in G in F: 1)AE=AG (this proves) 2) The quadrilateral AEFG is a diamond 4. In quadrilateral ABCD, AB=DC,? B=？ C & lt90. Verification: The quadrilateral ABCD is trapezoidal. Proof: 5. As shown in the figure: When the size is 6? In a square grid of 5, the vertices A, B and C of △ABC are on the vertices of the unit square. Please answer the following questions: (1) Draw a △DEF in the diagram so that △DEF∽△ABC (similarity ratio is not 1) requires that points D, E and F must be at the vertex of the unit square (you can use the existing one. (2) Write the proportional expressions of their corresponding edges; And find the similarity ratio of △DEF and △ABC. 6. Given AB=4, AC=2, D is the midpoint of BC, and AD is an integer, find AD. 7. it is known that d is the midpoint of AB. ACB=90？ , verification: CD =1/2ab.8. Known: BC=DE,? B=？ e，？ C=？ D and f are the midpoint of the CD, so verify:? 1=? 2.9. as shown in the figure: AB=AC, ME? AB，MF？ AC，e，f，ME=MF。 Verification: MB=MC 10. As shown in the figure, five equivalent relationships are given: ① ad = bc2ac = bd3ce = de4? D=？ C ⑤？ DAB=？ CBA。 Please take two of them as the conditions and one of the other three as the conclusion, draw the correct conclusion (write only one situation) and prove it. As shown in the figure: BE? AC，CF？ AB, BM=AC, CN=AB. Verification: (1) am = an; (2)AM？ Ann. 12. As shown in the figure, AB=DC, AC=DB and BE=CE are known. Proof: AE = de. 13. As shown in the figure, △ABC is an isosceles right triangle. ACB=90？ , AD is the middle line of BC side, crossing c is the vertical line of AD, intersecting with AB at point e and intersecting with AD at point f,