基础练习
1.70°
2.D
3.(1)四条边:EF ,FG ,GH ,HE;
四个内角:∠EFG ,∠FGH ,
∠GHE ,∠HEF;
对角线:FH ,EG
(2)略
(3)120°
4.36°,72°,108°,144°
综合运用
5.∠BOC = 80°
6.(1)由已知可证∠A + ∠ADC = 180°,
∴ DC∥AB
(2)由∠A = ∠C,∠ABD = ∠CDB ,DB = BD,
得△ABD ≌ △CDB
基础练习
1.70°
2.D
3.(1)四条边:EF ,FG ,GH ,HE;
四个内角:∠EFG ,∠FGH ,
∠GHE ,∠HEF;
对角线:FH ,EG
(2)略
(3)120°
4.36°,72°,108°,144°
综合运用
5.∠BOC = 80°
6.(1)由已知可证∠A + ∠ADC = 180°,
∴ DC∥AB
(2)由∠A = ∠C,∠ABD = ∠CDB ,DB = BD,
得△ABD ≌ △CDB