alright geometry guys

Discussion in 'Hardscaping' started by Dirt Digger2, Mar 28, 2010.

  1. Dirt Digger2

    Dirt Digger2 LawnSite Silver Member
    from PA
    Posts: 2,396

    i couldn't find the hardscaping section...i thought one was in here or i didn't look hard enough

    anyway...i am going to be pouring a pond for a fountain. The pond has a 2.5' radius and i will be pouring the concrete 3" thick so the inside of the pond will be 2.25'. I want a 3" overhang with a cut flagstone, so that will take the inside of the flagstone to 2' radius, the flagstone will be 12"x12" so the outside radius of the flagstone will be 3'.

    my question is, with a circumference on the outside of 28' (meaning i need 28 stones) at what angle should i be cutting off both sides of the stone to get a wedge shape that is uniform around....

    heres a few pictures to help visualize

    thank guys

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  2. cet

    cet LawnSite Member
    from Toronto
    Posts: 89

    The circle is 360 degrees. You have 28 pieces so that is 56 cuts. 360 divided by 56=6.4285714.

    That's my guess.
     
  3. gomowdig

    gomowdig LawnSite Member
    Posts: 40

    First of all DirtDigger2, you might find someone with a degree in CE from Penn State....
    But since I always got a real kick out of your farming and dirt moving, I'll give it a shot.

    The outer circle of the pavers will have a diameter of 28/3.14 = 8.917 '; the inner circle of the pavers will be approximately 6.917 ' and have a circumference of 3.14 x 6.917 =21.719 '. Dividing by 28 pavers, you have to cut back to 0.776 ' for each paver. You will take off 1.000 - 0.776 =0.3243 ' Now divide by 2 for each side and you have the tangent of the angle = 0.1622 or 9 deg 13 min. I would just mark 0.1622 x 12 or about 1.95 in , make your cut line and saw away. Check my numbers; good luck.
     
  4. Dirt Digger2

    Dirt Digger2 LawnSite Silver Member
    from PA
    Posts: 2,396

    your right...i was sitting here thinking about it earlier and was having brain farts...but i got up and took a shower and figured it out on the steamy glass door with my finger haha...always have my best thinking time in the bathroom...anyway i will post pictures of the progress
     
  5. doubleedge

    doubleedge LawnSite Senior Member
    from ND
    Posts: 912

    I found that 19 stones that are 12" by 12" would work best:

    [​IMG]

    The outside radius is 36" at it's widest point; the inside radius is 24" at it's widest point.

    I used a free program called Google SketchUp to create it. It doesn't make mathematical miscalculations.
     
  6. AI Inc

    AI Inc LawnSite Fanatic
    Posts: 25,164

    This is actualy a lot easier then it would appear. Take your outside # and divide it by # of peices. Take your inside # and divide it by # of peices and that will give you your angle.
     
  7. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Posts: 6,401

    I'm gettin a kick out of that LITTLE hole was dug with a machine! Christ, it took more time to load and unload the machine than it would have for 2 of my guys to dig it :)

    Gotta love white people.........



    ,
     
  8. Dirt Digger2

    Dirt Digger2 LawnSite Silver Member
    from PA
    Posts: 2,396

    the little machine was also used to rip up the bulkhead board, dig the drain pipe line out from the pond, and move a pile of dirt...

    but she sure is cute though

    [​IMG]
    [​IMG]
     
  9. cet

    cet LawnSite Member
    from Toronto
    Posts: 89

    This looks like a pretty hard way to figure it out.

    Only problem is 1.000-0.776=0.224 not 0.3243. 1/2 of .224 is .112

    I think the answer is what I gave you in my first post.
     
  10. capelawncare.com

    capelawncare.com LawnSite Fanatic
    Posts: 8,136

    Looks like a long commute from Pa to that job...
     

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