1、 3 30 1 A 2 3 4 B 5 7 7 C 5 6 12 D 6 8 10 2 ABC AB A B C. D 2 3 AD ABC ABD 25cm AB AC 6cm ACD A 19cm B 22cm C 25cm D 31cm 4 A B C D 5 ABC DEF A AB=DE BC=EF A= D B A= D B= E C= F C AC=DF B= F AB=DE D B= E C= F AC=DF 10 3 6 9 6. Rt ABC C=90 BD ABC AC D DE AB E AC=3cm AE=2cm, AED A 3cm B 4cm C 2cm D 7.
2、 A B C D 8. A+ B= C A B C=1 2 3 B A= B= C ABC A 1 B 2 C 3 D 4 9. ABC O ABC A=4 BOC= A B C D 10. ABC DE A BCDE A 1 2 A A= 1+ 2 B 3 A=2 1+ 2 C 3 A=2 1+ 2 D 2 A= 1+ 2 3 30 11. AB CD 12. 3 5 13. _ 14. _ 11 13 14 15. A+ B+ C+ D+ E+ F+ G 16. Rt ABC ACB A CB CD _ 17. 4 1+ 2 _ 15 16 17 18. ABC AD BC BE ABD
3、AD ABC 24 ABE 18 19 20 19. ABC AD AE ABC DAE=_ 20. ACB AC=BC C 2 0 A 6 3 B 60 21. (9 ) ABC C= ABC=2 A BD AC DBC 22. 9 AC BD O AD=CB E F BD AE=CF DE=BF 1 D= B 2 AE CF 23. 9 ABC AB=AC AD BC D E F AB AC BE=CF DE=DF 24 . 9 A= B AE=BE D AC 1= 2 AE BD O AEC BED 25. 12 ACB ECD A C D BD AE AE BD F 1 ACE BCD 2 AE BD 26. 12 ABC AB=AC DE A BD DE D CE DE E 1 BC DE 1 AD=CE BA AC _ 2 BC DE 2 1 AB AC
