gmatprep2..geometry
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let angle BAO =x so angle BOA = x (ab =oc=ob)
so angle ABO =180 -2x
so angle CBO = angle BCO = 2x
hence angle BOC = 180-4x so angle COA = 180-4x+x =180-3x
and since COD =60degs hence COA =120 =180-3x
x=20
so angle ABO =180 -2x
so angle CBO = angle BCO = 2x
hence angle BOC = 180-4x so angle COA = 180-4x+x =180-3x
and since COD =60degs hence COA =120 =180-3x
x=20
Regards
Samir
Samir
Hi, samirpandeyit62---
How did you know that AB and BC formed the straight line AC? From the diagram, it looks like a straight line, but my understanding is that we can't always assume the diagram is to scale.
Thx,
K
How did you know that AB and BC formed the straight line AC? From the diagram, it looks like a straight line, but my understanding is that we can't always assume the diagram is to scale.
Thx,
K
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- Master | Next Rank: 500 Posts
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Hi Kansonne,
As per my knowledge of the directions for geomety questions, we can extract some data from the diagram like here we can say AC is a straight line, coz it clearly looks like that in the diagram, IMO if there was an angle then it would have been clearly shown (you see a lot of geometry questions rely on the fact that sum of two angles along a straight line is 180 degs) i.e AB and BC will appear to make an angle , coz then the ans would be E
As per my knowledge of the directions for geomety questions, we can extract some data from the diagram like here we can say AC is a straight line, coz it clearly looks like that in the diagram, IMO if there was an angle then it would have been clearly shown (you see a lot of geometry questions rely on the fact that sum of two angles along a straight line is 180 degs) i.e AB and BC will appear to make an angle , coz then the ans would be E
Regards
Samir
Samir