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Math Help - point symmetry

  1. #1
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    point symmetry

    Will a star have point symmetry? It looks like it does, but I was told that if I spin it 180 degrees and it looks the same it does, When I rotate it 180 degrees it does not look the same but about 70 degress it is the same. So how do I determine? Thanks
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  2. #2
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    It seems that you are talking about a 5-branch star
    When you rotate it 360/5 = 72 degrees it looks the same
    But when you rotate it 180 degrees it does not look the same, it is reversed
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  3. #3
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    Quote Originally Posted by running-gag View Post
    It seems that you are talking about a 5-branch star
    When you rotate it 360/5 = 72 degrees it looks the same
    But when you rotate it 180 degrees it does not look the same, it is reversed
    Yes it is a 5 point star it has rotational synmmetry at intervals of 72 degrees. I understand that. Will this 5-point star have point symmetry? this is what I am confused with, will an object only have point symmetry if turn the object up side down and it looks the same only 180 degrees and nothing else
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  4. #4
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    Talking

    Quote Originally Posted by algebraisabeast View Post
    Yes it is a 5 point star it has rotational synmmetry at intervals of 72 degrees. I understand that. Will this 5-point star have point symmetry? this is what I am confused with, will an object only have point symmetry if turn the object up side down and it looks the same only 180 degrees and nothing else
    Under the definition that point symmetry is rotational symmetry, but only in 180-degree increments, then you were correct that the five-pointed "star" will not have this symmetry, since it is visibly "different" when you've done a half-rotation.

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