Help working out a area

[Jimbob87]

Hi need help again with an area we have to turf. We have worked it out but want some confirmation as its a big area and dont want to get it wrong.

 

I have broken the area into 3 differant areas

 

Area 1

Top side 5m

side 1 5m

side 2 4m

bottom side 5m

 

Area 2

 

Top side 22m

side 1 22.5m

side 2 13.5m

bottom side 12.5m

 

Area 3 is a triangle

 

side 1 26m

side 2 25m

side 3 18.5m

 

Hope someone can help got to get it priced asap for a customer of ours who found 30 cows paddling round on his lawn:thumbup:

 

Many thanks James

[RobArb]

Area 1 - 22.5 sqm

 

Area 2 - There is no generalized formula for calculating the area of a quadrilateral given just the sides. You would need to specify at least one angle to make the answer unique.

 

For example, let's take a quadrilateral with all sides = 10. Now if this was a square (90 degree angles), then the answer is obviously 10² = 100 sq. units.

 

But a rhombus is also a valid quadrilateral with equal sides. A rhombus with sides of 10 would have a smaller area, than the square. In the worst case, if it had tiny angle and a really big angle, the area would be close to zero.

 

So unless you have a known angle, or perhaps a known diagonal (where you could calculate the area of the two triangles), there is no way to figure the area of the quadrilateral just given the measurements a, b, c, d for the sides without a diagram or angles

 

Area 3 - 1/2 base* height = area of triangle for right angle but doesn't sound like it is so would also need an angle to work out the area of an uneven triangle...

 

and that is with 3 bottles of big cider in me

 

 

that'll be £5.27 please for the 3 mins i've just spent writing this post:lol:

[Pedroski]

Area 2 - There is no generalized formula for calculating the area of a quadrilateral given just the sides. You would need to specify at least one angle to make the answer unique.

 

I beg to differ. Jimbob has measured all 4 sides, giving top, bottom and each side. He just needs to measure one diagonal then use this calculator Area Calculator

 

And the triangle is easy. Given 3 sides there's only one way the sides can be in relation to each other. You can draw it to scale using a compass and graph paper, then split the one triangle into two right angle triangles and measure area of each. Or use http://www.handymath.com/cgi-bin/irregangle12.cgi I calc the area as 219.48782 square metres.

£10.80 please Jimbob

 

Oops, sorry Rob - just seen you mentioned the diagonal of the rhombus!

Edited July 7, 2012 by Pedroski

[treequip]

I beg to differ. Jimbob has measured all 4 sides, giving top, bottom and each side. He just needs to measure one diagonal then use this calculator Area Calculator

 

£10.80 please Jimbob

 

I agree with that, that will be a fiver please Jim

[headgroundsman]

As area 1 is also a quadrilateral and you only know the dimentions and no angles or diagonal then you can not say the area either so give back your fee please lol

[RobArb]

dagnamit, scuppered again...

 

£3 please:blush:

[RobArb]

As area 1 is also a quadrilateral and you only know the dimentions and no angles or diagonal then you can not say the area either so give back your fee please lol

 

Ah but i know 3 sides are the same, so nearly a square...

 

5x5 = 25 sqm

 

but one of the sides is 4m, so if you took the area as (4x5) + (1x5/2) = 22.5 sqm

 

£2.50 then!

[Pedroski]

As area 1 is also a quadrilateral and you only know the dimentions and no angles or diagonal then you can not say the area either so give back your fee please lol

Area 1 is easy. Because 3 sides are the same and the 4th is only slightly shorter, then it's not far off the area of a square.

 

Rob - beat me to it.

Edited July 7, 2012 by Pedroski
Rob posted just what I was going to say!

[RobArb]

as above pedro, as above:thumbup:

 

ok ok £2.50 and thats my final offer:biggrin:

[headgroundsman]

need not be square could be nearly rhomboid so area could be as you said or near to zero

Edited July 7, 2012 by headgroundsman