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Math Help - Unknown angles on lines

  1. #1
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    Unknown angles on lines

    New Microsoft Word Document.doc

    i want to know how to solve these two questions.
    Its a Microsoft office file with two figures in it.
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  2. #2
    Junior Member masoug's Avatar
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    The first question can be figured out, assuming that the two lines are parallel...

    Bisect the angle x with a parallel line to the other two.
    Then the parallel line property can determine the two angle measures adjacent to x.
    If the lines are not parallel, then this method won't work.

    -Masoug
    Attached Thumbnails Attached Thumbnails Unknown angles on lines-angles.jpg  
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  3. #3
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    Can u explain it a bit more ?
    and what about the 2nd figure ?
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  4. #4
    MHF Contributor Unknown008's Avatar
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    In the diagram masoug posted, can you see the 'Z' formed by the parallel lines and the diagonals?
    You should know that angles that are in the corners of the 'Z' are equal.

    From this, you get to know the 56 and 41 angles.

    Now, total angle is 360. You have 56 and 41. So the remaining is x = 360 - (41 + 56) = 360 - 97 = 263 degrees.

    For the next one, look at the sketch, and use what you know to find X.



    Find angles a and b first. X should come easy if you learned what to do in the first part.

    Of course, there are more ways to do it, but I'd like you to do it the way you solved the first part.
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  5. #5
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    But why did he write 115 in his attached figure.that confused me.Now i can understand it.thanks
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  6. #6
    MHF Contributor Unknown008's Avatar
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    Well, his answer is wrong because you can clearly see that the angle is a reflex angle, but 115 is obtuse. I hope you understand it
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  7. #7
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    a=360-247=113

    b=360-248=112

    so 113+112=225
    and 360-225=135=x
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  8. #8
    MHF Contributor Unknown008's Avatar
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    You missed something.

    a = (360 - 90) - 247
    b = (360 - 90) - 248

    Can you try again?
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  9. #9
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    i get it

    a = (360 - 90) - 247=23
    b = (360 - 90) - 248=22

    a+b=23+22=45

    x=360-45=315
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  10. #10
    MHF Contributor Unknown008's Avatar
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    Great! Well done!
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