For math experts

Discussion in 'Computer Support' started by John Smith, Nov 30, 2003.

  1. John Smith

    John Smith Guest

    I have no access to a proper protractor to do this with so I need to know what
    the measurements are in cutting an angle.
    Assume we have at our disposal a standard 2x4 and wish to cut a 60 degree angle.

    What would the measurement be from the right side of the edge to the left most
    edge of the triangle?
    Assuming the top right edge is one corner, and the lower right edge is another
    corner.

    Or if you have a 60 degree fixed angle guide handy, measure each side and let me
    know what they are. Thanks.
     
    John Smith, Nov 30, 2003
    #1
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  2. John Smith

    MrToad Guest

    Ever hear of using cardboard as a template?
    Even a piece of paper will do....
     
    MrToad, Nov 30, 2003
    #2
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  3. John Smith

    Brian H¹© Guest

    John Smith said:
    Draw a line between the 2 points, divide it into 10 equal lengths, cut at the
    6th division.
     
    Brian H¹©, Nov 30, 2003
    #3
  4. John Smith

    Brian H¹© Guest

    Brian H¹© said:
    Oops, before you get your saw out, redraw with 9 divisions, not 10.
     
    Brian H¹©, Nov 30, 2003
    #4
  5. Got a graphics program? Some/most of the good ones will, when you draw
    a line, tell you its angle. Draw one that shows as 60 degrees. Print
    it. Transfer it to your stock.
     
    Blinky the Shark, Nov 30, 2003
    #5
  6. John Smith

    Richard Guest

    Good idea. But what if you're out in the field and have only a hand saw, a
    ruler, and a pencil?
    Knowing that the height of the triangle is going to be 4 inches, what is the
    length of the base of the triangle?
    If the base length is also 4 inches, we know that will give us a 45 degree
    cut right?
    So to get 60 degrees, the base line length would be shorter yes?
    So what's the length needing to be?

     
    Richard, Nov 30, 2003
    #6
  7. John Smith

    -= Hawk =- Guest

    The subject says 'for math experts', it makes no mention
    of moronic, unemployed pedophiles.
     
    -= Hawk =-, Nov 30, 2003
    #7
  8. I'd be screwed.
    For starters, a 2x4 isn't 2" x 4", so you're already in trouble if you're going
    to use a math approach, as you'll be starting from an incorrect dimension.
    Yes, with base and alt the same -- not that those even-inch dimensions apply to
    a 2x4.
    Or longer, depending on which vertex you wanted to be 60 degrees.
    Dunno. Your limitations of what I have on hand don't include trig tables.

    I'll trade you that ruler for a compass. Don't need the ruler; could do this
    with the compass.
     
    Blinky the Shark, Nov 30, 2003
    #8
  9. John Smith

    Cicero Guest

    ===========
    On most ordinary wood saws you'll find that the front part of the handle
    is designed with both 90 degree and a 60 degree angles built in.

    Cic.
     
    Cicero, Nov 30, 2003
    #9
  10. John Smith

    -= Hawk =- Guest

    RtS started from a dimension of extreme stupidity.
     
    -= Hawk =-, Nov 30, 2003
    #10
  11. John Smith

    Brian H¹© Guest

    Blinky the Shark said:
    It is if it is planed.
     
    Brian H¹©, Nov 30, 2003
    #11
  12. John Smith

    anthonyberet Guest

    I dont think that will work anyway......... what you are describing would
    work along an arc but not where there is a straight edge involved.
     
    anthonyberet, Nov 30, 2003
    #12
  13. John Smith

    Patrick Guest

    I've come up with a ratio of;
    1 , 1.7320508075688772935274463415059

    i.e. one side is to be ~1.7 times the other side

    1|__
    ~1.7
     
    Patrick, Nov 30, 2003
    #13
  14. John Smith

    anthonyberet Guest

    Use this right-angled triangle calculator:
    http://www.ex.ac.uk/trol/scol/calrtri.htm

    If I understand you correctly the top right corner will be 6.93 inches above
    the lower left corner, measured along the length of the 2x4.
    The line between them (the hypotenuse) will be 8 inches.
     
    anthonyberet, Nov 30, 2003
    #14
  15. John Smith

    ve3mdn Guest

    This may be silly and not help. The easiest way to create a 60 degree angle
    is to draw a triangle with all sides the same. As long as it is large enough
    any side can be used as the base along the length of the board. If you want
    a 30-60-90 triagle use even numbers for the previous triangle anmd measure
    half way across on of the sides and draw a line to the opposite side.
    Basically just fold the previous triangle in half. If you want the math the
    side across from the 30 is 1 unit the side across from the 90 is 2 units and
    the side across from the 60 is 1.7321units (square root of 3).

    Eric
     
    ve3mdn, Nov 30, 2003
    #15
  16. John Smith

    Patrick Guest

    Haveing seen 'anthonyberet' post, it appears that the hypotenuse is to be
    twice the length of one of the other sides.
    a
    1|__b
    ~1.7 line ab=2
     
    Patrick, Nov 30, 2003
    #16
  17. John Smith

    anthonyberet Guest

    I am not sure that I visualised the OP's problem properly, however the
    calculator i linked to should solve his problem.
    If Angle B is the one to be 60 degrees (I at first used angle A), then the
    top corner would be 2.31 inches above the first and the hypotenuse 4.62
    inches.
     
    anthonyberet, Nov 30, 2003
    #17
  18. John Smith

    bb3 Guest

    Not in the US.
    http://www.allexperts.com/previousqv.asp?QuestionID=3160186

    <snip>
     
    bb3, Nov 30, 2003
    #18
  19. 2x4s are smaller than 2x4. How is planing going to make them larger?
     
    Blinky the Shark, Nov 30, 2003
    #19
  20. That's exactly correct.[1] That's why protractors are round.

    [1]Even with the nine sections to which he correcected this original.
     
    Blinky the Shark, Nov 30, 2003
    #20
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