finding area of irregular mulch beds?

Discussion in 'Landscape Architecture and Design' started by lasher66, May 9, 2006.

  1. lasher66

    lasher66 LawnSite Senior Member
    Posts: 395

    Ok, I messed up. I measured a landscape area to be mulched and I measured the circumference around the irregular shaped mulch beds and thats it. Is there a way to find square ft from the circumference of an irregular area alone? For some stupid reason, I was thinking that if you took a rope and made a circle, you could bend it to different shapes and the area would still be the same inside it. From my calculations so far, I dont think this is true. I know I should have just divided it into rectangles and came up with a close figure. The circumference of the area is 364 ft. Any help would be greatly appreciated. Thanks

    Jason
     
  2. procut

    procut LawnSite Bronze Member
    Posts: 1,853

    Using the circumference of 364' that you gave, I made a few quick calculations, and get a little over 10,000 sq. ft. Not 100% sure if it is correct though. hope it helps!
     
  3. procut

    procut LawnSite Bronze Member
    Posts: 1,853

    I just realized something else, it would have to be a perfect circle for that figure to be correct.
     
  4. lasher66

    lasher66 LawnSite Senior Member
    Posts: 395

    Yeah, I already went back and remeasured the beds. I found that there is no way to decide the area just by the circumference. Just another dump mistake I made. Thanks anyways.

    Jason
     
  5. Critical Care

    Critical Care LawnSite Bronze Member
    Posts: 1,654

    Don't think you can do it on circumference alone, but there are different ways to figure irregular shaped areas. For an area that is roughly circular in shape, pick out a spot that is close to the center of the area. Measure the distance from the center to the outside in every 10 degree increments, or so. From this information you can get a good average on the radius. Now you just solve for the area of a circle, which can be figured .785 x d x d.

    For a shape like the one below, measure across the longest length (red) and then take the average of a number of cross distance measurements (green). Then just figure as a rectangle.

    area.gif
     
  6. kemmer

    kemmer LawnSite Senior Member
    Posts: 608

    Or just do this

    untitled.JPG
     
  7. KenH

    KenH LawnSite Bronze Member
    from CT
    Posts: 1,622

    10,201 using the circumference you gave.

    If you take a string and outline the bed, you can get the circumference (364'). Once you have the circumference, use c/d = pi to get the diameter (115'). Once you have the diameter, take 1/2 that to get the radius (57'). Then use a= pi * r squared to get the area. (10201)
     
  8. scott's turf

    scott's turf LawnSite Senior Member
    from NH
    Posts: 949

    I think you mean perimeter not circumference. A circumference is only for a circle not the irregular shape you describe. Unfourtunally a perimeter will not give you an area unless you know the type of shape it is.
     
  9. KenH

    KenH LawnSite Bronze Member
    from CT
    Posts: 1,622

    Let me ask, if you have a string, lets say 40' long, would it matter if it was made into the shape of a square (5'sides) or a circle...wouldnt the area inside remian the same and just the outside shape change??? ie, as long as the sting stays the constant length, any shape you make out of it should come up with the same area, right???

    Maybe Im confusing myself, but if you take the shape above, measured the outline with a string, then made that into a circle, coundnt you find the area that way???
     
  10. lasher66

    lasher66 LawnSite Senior Member
    Posts: 395

    That is exactly what I was thinking, BUT if you take the string and make an oval, almost to the point to where the two side of the string are touching, there is almost no area with the same perimeter. So that is how I proved myself wrong. Plus I took different shapes like squares and rectangles and gave them different length side,but made is so all the sides added up to the perimeter I came up with, the results showed different areas in each when using Length times width. So you have to use the methods for perfect circles or other shapes to find area.

    Jason
     

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