#How would I find the blue section's area?

61 messages · Page 1 of 1 (latest)

next gale
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best i can do is approximate with triangles

winter marlin
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for help, use #1015578016606343218 or #1020426321261756536

orchid depot
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You can split it up in a square and 4 diskcaps

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Those caps have a calculable area

spark stump
# next gale

have you heard of inclusion exclusion principle

spark stump
shell orchidBOT
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Coffeλ

spark stump
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$\abs{A} +\abs{B} - \abs{A\cap B}$

shell orchidBOT
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Coffeλ

spark stump
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can we do this for 3 sets

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4 sets?

orchid depot
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But then you still need to calculate area of diskcaps, don't you

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Do you know how to calculate the area of a disksegment? (A piece of pie)

orchid depot
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I meant OP

spark stump
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@orchid depot rotation conserves area right

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tilt the picture 45 degrees

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then we can find them easily.

orchid depot
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?

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Why does that make it easier in any way

spark stump
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I'd demonstrate

orchid depot
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I guess the distance between the centers is sqrt(2) for closest and 2 for furthest

spark stump
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let's assume radius = r and distance of each centre from origin = d

orchid depot
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I think you only need radius chosen, the distance between the circles gets fixed by putting the centers on other circles

spark stump
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when it's spun 45deg(wlog, let's say clockwise)
the centre of bottom left circle is moved to (-d/sqrt(2),-d/sqrt(2)) = let, (-k, - k)
now we can make the equation of this circle :
(x+k)^2 + (y+k)^2 = r^2
now we just have to calculate the area this covers in the ++ quadrant

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and the blue area is 4x that

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what does translating a circle from (0,0) to (-k, - k) do to the area on the positive x quadrant?

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something like this might help too

orchid depot
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Why do you want to translate a circle

next gale
next gale
orchid depot
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It's a fraction of the disk's area

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You can prove it by approximating the disk with triangles

next gale
next gale
orchid depot
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I am talking about this

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This kind of pie

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Not the caps

next gale
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OH!

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waitaminute

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that should have been somewhat obvious how did i not think of that

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im an idiot

next gale
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0.732^2 + 4(area of segment of circle - area of triangle) = blue area

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witha little bit of trig i think i can solve it

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thx

next gale
next gale
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A ≈ 4{(2π×(2sin⁻¹(0.366/√2)/360)) - ((√[2-0.366²])(0.366)(0.5))} + 0.732²

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Is that abt right?

orchid depot
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Approximately, becuz 0.366 is an approximation

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Well done!

next gale
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:D

next gale
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?

ebon river
hybrid scrollBOT
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-2×sqrt(3) - 4×sqrt(-5 + 3×sqrt(3)) + 2×π/3 + 4 = 0.858729555779608

ebon river
# next gale ?

upon using integration, im getting another solution which is 2*(1+π/3-sqrt(3))