6. 如图,$∠ 1 = ∠ 2$,$∠ 3 = ∠ 4$,有下列结论:①$AD$平分$∠ BAE$;②$AF$平分$∠ EAC$;③$AE$平分$∠ DAF$;④$AF$平分$∠ BAC$;⑤$AE$平分$∠ BAC$. 其中正确的有 (

A.4个
B.3个
C.2个
D.1个
C
)A.4个
B.3个
C.2个
D.1个
答案
6. C
7.(雨花区期末)如图,OC是∠AOB的平分线,∠DOC=3∠BOD,∠BOD=18°,则∠AOD的度数为 (

A.72°
B.80°
C.90°
D.108°
C
)A.72°
B.80°
C.90°
D.108°
答案
7. C
8.计算:
(1)$13°24'15''×5 =$
(2)$58°34'16''÷4 =$
(1)$13°24'15''×5 =$
67°1'15''
;(2)$58°34'16''÷4 =$
14°38'34''
.答案
8. (1)67°1'15'' (2)14°38'34''
9. 如图, 已知OE平分∠AOB, OF平分∠BOC, ∠EOF=65°, 则∠AOC=

130
°。答案
9. 130
10. 如图,已知$∠ AOB = 108°$,$OE$是$∠ AOB$的平分线,$OC$在$∠ AOE$内.
(1)若$∠ COE = \dfrac{1}{3}∠ AOE$,求$∠ AOC$的度数;

(2)若$∠ BOC - ∠ AOC = 18°$,求$∠ COE$的度数.
(1)若$∠ COE = \dfrac{1}{3}∠ AOE$,求$∠ AOC$的度数;
(2)若$∠ BOC - ∠ AOC = 18°$,求$∠ COE$的度数.
答案
10. (1)解:∠AOC = 36°.
(2)解:∠COE = 9°.
(2)解:∠COE = 9°.
11.如图,点E,O,A在同一直线上,OC平分∠AOD,且∠2:∠3:∠4=1:2:4,求∠1的度数.

答案
11. 解:∠1的度数是22.5°.
12.(前进区期末)已知:OC,OD是∠AOB内部的射线,OE平分∠AOC,OF平分∠BOD.
(1)若∠AOB = 120°,∠COD = 30°,如图①,求∠EOF的度数;
(2)若∠AOB = α,∠COD = β,如图②,请直接用含α,β的式子表示∠EOF的大小.

(1)若∠AOB = 120°,∠COD = 30°,如图①,求∠EOF的度数;
(2)若∠AOB = α,∠COD = β,如图②,请直接用含α,β的式子表示∠EOF的大小.
答案
12. 解:(1)∠EOF = 75°.
(2)∠EOF = $\frac{1}{2}(α+β)$.
(2)∠EOF = $\frac{1}{2}(α+β)$.
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