Pie day

[Tin Pot]

http://www.piday.org

Today is Pi day!

How will you celebrate the ratio of radius to perimeter?!

Apologies @vernon @Piemaster et al.

 

[vernon]

By solving this puzzle.

Show that the blue and red areas are equal in size.

 

[Piemaster]

No pies at all. Not sure the locals (Brazil) know what a pie is.
I will be considering the specification of a length of pipe, in which a nominally sized 4" pipe does not have, however you measure it, a 4" diameter.

 

[vernon]

I will be considering the specification of a length of pipe, in which a nominally sized 4" pipe does not have, however you measure it, a 4" diameter.

That's a close relative of the 2 x 1 timber paradox where no timber, irrespective of finish, type or retailer source actually measures 2" x 1" in cross section.

 

[Piemaster]

And then there is metric inches. An exclusive to the world of some oil installations in which there is 10" to the foot.

 

[newfhouse]

And then there is metric inches. An exclusive to the world of some oil installations in which there is 10" to the foot.

Not quite exclusive. When I worked at the BBC in the 1980s I recall seeing rulers and tape measures calibrated in metric feet and inches, a foot being 300mm and a metric inch being 30mm. They were shown to me as a curiosity - I think they had fallen out of use some years before.

 

[vernon]

Not quite exclusive. When I worked at the BBC in the 1980s I recall seeing rulers and tape measures calibrated in metric feet and inches, a foot being 300mm and a metric inch being 30mm. They were shown to me as a curiosity - I think they had fallen out of use some years before.

It is exclusive. There's a world of difference between 10" to 1' (254mm) and 300mm to 1'.

If they metricated mass to 10lb to the stone - I'd still need liposuction to have a 'healthy' BMI.

 

[Cubist]

A pie chart for you

 

[newfhouse]

It is exclusive. There's a world of difference between 10" to 1' (254mm) and 300mm to 1'.

You're right. A search reveals ISO2848 which differs from my recollection of a metric inch being a tenth of a metric foot but does reference BBC Television Centre. Maybe there was more than one standard, a bit like there being different values for pi...

 

[Piemaster]

Oil industry makes no sense. A tank on a ship or rig has a volume and with very few exceptions it will be given in cubic metres. I'm sure there are those who are just being smartarses when they give you a weight in metric tonnes, then a specific gravity in pounds/cubic foot to convert it. Barrels are quite popular too, though easier to convert.
I've delivered liquids to places where the hierarchy have asked for x tonnes and duly converted it from m3, and just know my oppo actually doing the job is converting it back again...

 

[PK99]

By solving this puzzle.

Show that the blue and red areas are equal in size.

Let Radius of large circle be R

Let each white are be White
.......
Thus, radius of small circle is R/2
......

1 Area of quadrant = (pi) (R^2)/4 = A

2 Area of two semi circles = (pi) (R/2)^2 = (pi) (R^2)/4 = A
......

Consider Quadrant

2White + Blue + Red = A

Consider semicircles:

(White + Blue) * 2 = A

Therefore,
2White + Blue + Red = (White + Blue) * 2

2White + Blue + Red = 2White +2Blue

Blue +Red = 2Blue

Red = Blue

QED

 

[Shut Up Legs]

Let Radius of large circle be R

Let each white are be White
.......
Thus, radius of small circle is R/2
......

1 Area of quadrant = (pi) (R^2)/4 = A

2 Area of two semi circles = (pi) (R/2)^2 = (pi) (R^2)/4 = A
......

Consider Quadrant

2White + Blue + Red = A

Consider semicircles:

(White + Blue) * 2 = A

Therefore,
2White + Blue + Red = (White + Blue) * 2

2White + Blue + Red = 2White +2Blue

Blue +Red = 2Blue

Red = Blue

QED

I was about to post my own solution, derived without the aid of Google, but with a spoiler. Now you've gone and spoiled that. Nobody will believe I did it without help, now.

 

[jefmcg]

Pi day is an abomination from people who don't understand that you list units from least significant to most, or vice versa.

Ie 2016-03-14 yeah, (but no one uses this) or 14-03-2016 yeah (but no pi for you!) or 03-14-2016 yeah (but no one who understands numbers would use this!!)

hate hate hate

 

[TVC]

I like to have sex with 3.14 people at once, I'm pi-sexual.

 

[raleighnut]

That's a close relative of the 2 x 1 timber paradox where no timber, irrespective of finish, type or retailer source actually measures 2" x 1" in cross section.

With timber a length of 2x1 PAR started off as 2x1 sawn and then it was planed down smooth (Planed All Round) hence it is smaller.
Even more strangely timber is sold/priced by the cubic foot