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dave-lindell
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The area of the square with side a equals the area of circle with radius r.

The large square they are within has area of 1.00000

What are a and r?

Attached files

sqeqcirc.pdf (1.4 KB) 


 
Posted : August 22, 2015 6:07 pm
bill93
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a=0.556, r=0.314 Purely algebraic solution that I'll post later.


 
Posted : August 22, 2015 8:06 pm
dave-lindell
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Your circle and square don't fit into the big square.


 
Posted : August 22, 2015 11:45 pm
Doug Crawford
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a=0.5
r=0.293


 
Posted : August 23, 2015 2:59 am
squowse
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by algebra i get a=0.509 and r=0.287 on first attempt. I haven;t checked it though, just 3 mins. didn;t realise how rusty i was.
I will check by autocad.


 
Posted : August 23, 2015 5:51 am

squowse
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yay I think I got it.

Attached files

puzzle.dwg (35.4 KB) 


 
Posted : August 23, 2015 5:56 am
Doug Crawford
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Doug Crawford, post: 333110, member: 9 wrote: a=0.5
r=0.293

This is the answer,for a using the a quarter of big square, but the answers are
dependent, on each other.

a can be = 0 to 1
and r will vary
from .5 to 0


 
Posted : August 23, 2015 7:44 am
stephen-ward
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Doug Crawford, post: 333121, member: 9 wrote: This is the answer,for a using the a quarter of big square, but the answers are
dependent, on each other.

a can be = 0 to 1
and r will vary
from .5 to 0

He also stated that the areas of the small square and the circle must be equal.


 
Posted : August 23, 2015 8:33 am
Doug Crawford
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Stephen Ward, post: 333125, member: 1206 wrote: He also stated that the areas of the small square and the circle must be equal.

I stand corrected, thanks.

Now all I need are my chicken scratchings from 5:00 AM. this morning


 
Posted : August 23, 2015 9:23 am
mathteacher
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I got Bill93's answer with a quadratic equation. a = 0.5562092371, r = 0.3138074579. For those who hate lots of decimal places, remember that it's impossible to square a circle, so there is no exact answer.

But that's not the correct answer.


 
Posted : August 23, 2015 9:59 am

bill93
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I found my mistake. Darn 3-minute hurry.
Still all algebraic - no quadratic required. Just add up the pieces of the diagonal. Lots of sqrt 2 and sqrt pi factors.

Rounded to 4 places ...
a=0.5094
r=0.2874


 
Posted : August 23, 2015 10:24 am
mathteacher
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That's what I got. An "exact answer" for r is r = sqrt(2)/(1 + sqrt(2pi) + sqrt(2)). Bill probably has a simpler expression, but I've always done things the hard way!


 
Posted : August 23, 2015 12:37 pm
mathteacher
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squowse, post: 333115, member: 7109 wrote: by algebra i get a=0.509 and r=0.287 on first attempt. I haven;t checked it though, just 3 mins. didn;t realise how rusty i was.
I will check by autocad.

No outward signs of rust!!


 
Posted : August 23, 2015 12:59 pm