配套习题- 如何利用分类讨论思想解决复杂的角度计算 -【青果学院】

1/5单选题

难度：

1.已知∠AOB=45°，OC是∠AOB的一条三等分线，则∠AOC的度数是（）

A	15°
B	30°
C	15°或30°
D	不能确定

正确答案：Qw==

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

2/5单选题

难度：

2.已知∠AOB=60°，从顶点O引一条射线OC，使∠AOC=20°，则∠BOC=（）

A	20°
B	40°
C	80°
D	40°或80°

正确答案：RA==

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

3/5单选题

难度：

3.如图，OC是∠AOB的平分线，OD是∠BOC的平分线，若∠AOB=140°，则∠AOD等于（）

A	120°
B	105°
C	75°
D	70°

正确答案：Qg==

PGRpdj7op6PnrZTvvJriiLVPQ+aYr+KIoEFPQueahOW5s+WIhue6v++8jOKIoEFPQj0xNDDCsO+8jDxicj7iiLTiiKBBT0M94oigQk9DPTxpbWcgd2lkdGg9NiBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC8wMC82RS9yQkFDRkZNTVdwSERqYVhrQUFBQkhCRUpaYncwMTUucG5nIj7iiKBBT0I9PGltZyB3aWR0aD02IGhlaWdodD00MiBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzAwLzZFL3JCQUNGRk1NV3BIRGphWGtBQUFCSEJFSlpidzAxNS5wbmciPsOXMTQwwrA9NzDCsDwvZGl2PjxkaXY+4oi1T0TmmK/iiKBCT0PnmoTlubPliIbnur/vvIw8YnI+4oi04oigQ09EPTxpbWcgd2lkdGg9NzIgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMjMvNUQvckJBQ0UxTU1XcEdqdWlfRUFBQUItV2lWa0VzOTg2LnBuZyI+w5c3MMKwPTM1wrDvvIw8YnI+4oi04oigQU9EPeKIoEFPQyviiKBDT0Q9NzDCsCszNcKwPTEwNcKwLiA8YnI+5pWF6YCJQi4gPC9kaXY+

4/5单选题

难度：

4.∠AOB=45°，∠BOC=75°，OD平分∠AOB，OE平分∠BOC，则∠DOE=（）

A	60°
B	75°
C	60°或15°
D	70°或15°

正确答案：Qw==

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

5/5单选题

难度：

5.

已知在平面内，∠AOB=50°，∠BOC=20°，则∠AOC的度数是（）

A	30°
B	70°
C	30°或70°
D	20°或70°

正确答案：Qw==

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