Oast house, problem calculating

[WoodYouLike]

Not sure if it belongs here, but I'll give it a try and see where it ends up.

Ok guys, need your help with a calculation (not good at 'strange' math things).
Oast house has diameter 4.8 meter, how many square meters is that?? Please?

 

[kevplumb]

pi x r squared i think

 

[JohnD]

radius is 2.4m

area is (pi r) squared

so approx

(3.141582 x 2.4)2

(7.5397)2

but if you allow 15% wastage because it is round

call it 65m2

 

[WoodYouLike]

Thanks guys.
I'll make that 57 sq m ? Starts to look like a great job then (not sure hubby would be so happy though )

 

[johnny_t]

Beg to differ on the position of JohnD's brackets, as that implies you do the pi x r first and then square the whole lot, whereas you do the r-squared first and then multiply by pi.

Answer is about 18.1 sq.m though, but I gues you need to allow a lot more for offcuts than usual as you are not going to have square ended boards that you can just start the next row with.....


(Imagine it was a 5m x 5m square, that would be 25 sq.m. Chopping the corners off is not going to magically make it 57 sq.m, is it now.....)

 

[DidgePlayer]

18.1 metres approx.

Calculate as follows Radius squared multiply by pi (3.142 approx).

Radius is half the diametre so 2.4 x 2.4 x 3.142.

Here is an online calculator for you

http://www.calculateme.com/cArea/AreaOfCircle.htm

 

[JohnD]

how I wish I could remember pi.
..3...1....4....1...5.........8..........2

 

[JohnD]

Beg to differ on the position of JohnD's brackets, as that implies you do the pi x r first and then square the whole lot, whereas you do the r-squared first and then multiply by pi.

You mean pi (r 2)?



pi ( 2.4 x 2.4)

3.141582 x 5.76

so about 18.1 plus (lots of ) wastage

stupid boy John.

 

[WoodYouLike]

Answer is about 18.1 sq.m though, but I gues you need to allow a lot more for offcuts than usual as you are not going to have square ended boards that you can just start the next row with.....
(Imagine it was a 5m x 5m square, that would be 25 sq.m. Chopping the corners off is not going to magically make it 57 sq.m, is it now.....)

That's the feeling I had too. 4.8 x 4.8 = 23 sq m, 'chopping' off a bit for the round area and including extra waste makes 20 sq m.
Wasn't that far off then (and not as 'stupid' as I thought)

 

[WoodYouLike]

http://www.calculateme.com/cArea/AreaOfCircle.htm[/QUOTE]
Thanks for the link, lots of Oast houses around here, so might come in handy next time

 

[breezer]

but do bear in mind the answer is the exact area in square units.

it does not take into consideration off cuts for the material you "can not use"

 

[kevplumb]

will i get my caravan floor out of this LOL

 

[WoodYouLike]

will i get my caravan floor out of this LOL

lots of little pieces, yes sure! We'll make it into a jig-saw puzzle for you

 

[2scoops0406]

how I wish I could remember pi.
..3...1....4....1...5.........8..........2

3.141592

Off day?

 

[empip]

A shedload of on-line calculators :-
http://www.cleavebooks.co.uk/scol/index.htm

Noteworthy...
http://www.cleavebooks.co.uk/scol/ccalcoh2.htm

Even more calculators ....
http://www.martindalecenter.com/Calculators.html
Perhaps useful for sparky types..
http://www.martindalecenter.com/Calculators4A_1_E.html#ELEC-ELT

Here is one for the oldies ...
http://www.syssrc.com/html/museum/html/sims/javaslide/