irregular yard deminsions to acres
by Brick Mock on 07/18/04 at 19:38:53

i am trying to figure out hoe to convert the area at my home. the yard is not set at right angles. i would like to know the formula how to figure it. if it was 100 feet by 100 feet that would be simple. but this is mine...

(all in feet) 230 x 243 x 186 x 296

I would love to know the sq. feet and acres, plus how you convert the odd peremiters.

Thanks Brick

Re: irregular yard deminsions to acres
by Robert Fogt on 07/18/04 at 23:50:25

The only way to calculate the area of an irregular polygon, is to also know either one of the angles, or the length of one diagnal.

Measure the length of one of the diagnals, that will be enough to figure it out.

Re: irregular yard deminsions to acres
by Robert Fogt on 07/30/04 at 19:37:26

I have the values of the diagnals from your previous post, but you didn't mention which diagnal was for which.

[quote]I've gotten those other measurements. This is rough though. nw corner 88 deg, sw corner 92 deg, se corner 74 deg, ne corner 104 deg. Only adds up to 358 deg. May have to adjust a little. or I have the diags which were measured with the wheel and some eyeballing (house in the middle of the measuring area).
316.5 and the other was 357 feet. This doesn't have to be perfect just wondering how big the yard is how it is calculated. Thanks again, Brick[/quote]

But I can explain how to calculate it yourself.

What we do, is split the area into two separate triangles, then calculate the area of each triangle separately using Heron's formula.

Heron's formula is:
Area = sqrt(s(s-a)(s-b)(s-c))
Where s = (a+b+c)/2

The first triangle, a = 230, b = 243, c = 216.5
Solve for s:
s = ( 230 + 243 + 216.5) / 2 = 344.75
Now enter into Heron's formula:
Area = sqrt(344.75(344.75 - 230)(344.75 - 243)(344.75 - 216.5)) = 22720.8398 square feet

The second triangle, a = 186, b = 296, c = 216.5
Solve for s:
s = (186 + 296 + 216.5) / 2 = 349.25
Now enter into Heron's formula:
Area = sqrt(349.25(349.25 - 186)(349.25 - 296)(349.25 - 216.5)) = 20075.7544 square feet

Adding the area of the two triangles together for the total area of the yard:
22720.8398 + 20075.7544 = 42796.5942 square feet

Keep in mind that you did not post which sides went with which diagnal, so you will need to recalculate the area using the correct sides. This was just to show you how it was done.

Re: irregular yard deminsions to acres
by Brick Mock on 07/31/04 at 17:25:59

WOW! I really wish I had not slept through math class now. But I am printing out your suggestion and would like to try it. I really appreciate your response. Thanks Brick

Re: irregular yard deminsions to acres
by billman on 12/04/04 at 21:36:43

I say it is 1.3 arce

Re: irregular yard deminsions to acres
by brick mock on 12/05/04 at 13:32:29

Thanks billman. I came up with something close to that. Since the father-in-law just started putting in pipe fence without any real idea on where he was going with it it turned out odd. Thanks again

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