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Happy Square Root Day

Happy Square Root Day

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So how many squares are there on a chessboard? - And 64 is not the answer.

2 edits
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Originally posted by AttilaTheHorn
So how many squares are there on a chessboard? - And 64 is not the answer.
203

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Originally posted by lausey
203
No

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Originally posted by AttilaTheHorn
No
Oops, missed one. 204. 😕

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Originally posted by wormwood
they're just exponents for complex analysis.


and I can see why: everything is just so much simpler on complex plane.
Real, imaginary, or some combination thereof, that was a nice post.

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still wrong

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Originally posted by lausey
Oops, missed one. 204. 😕

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Originally posted by lausey
Oops, missed one. 204. 😕
Sorry I'm messing up these posts. -- 204 is not the correct answer.

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I must be asleep. 204 is indeed the correct answer.
The formula is 1² + 2² + 3² + 4² + 5² + 6² + 7² + 8² = 204.

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What about the number of rectangles?

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Originally posted by Palynka
What about the number of rectangles?
I worked out that it is 1092.

If you think of a rectangle of 1 square by 2 (1x2). That can go 7 across and 8 down (or vice versa) so that is 8*7 times it fits in the 64 squares.

For the others:

1x3=6*8
1x4=5*8
1x5=4*8
1x6=3*8
1x7=2*8
1x8=1*8

2x3=6*7
2x4=5*7
2x5=4*7
2x6=3*7
2x7=2*7
2x8=1*7


3x4=5*6
3x5=4*6
3x6=3*6
3x7=2*6
3x8=1*6

4x5=4*5
4x6=3*5
4x7=2*5
4x8=1*5

5x6=3*4
5x7=2*4
5x8=1*4


6x7=2*3
6x8=1*3

7x8=1*2

Simplified:

8(7+6+5+4+3+2+1) + 7(6+5+4+3+2+1) + 6(5+4+3+2+1) + 5(4+3+2+1) + 4(3+2+1) + 3(2+1) + 2

8*28 + 7*21 + 6*15 + 5*10 + 4*6 + 3*3 + 2 = 224 + 147 + 90 + 50 + 24 + 9 + 2 = 546

This is for the rectangles going in one direction, for the other direction, multiply by 2 to get 1092.

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Originally posted by lausey
I worked out that it is 1092.

If you think of a rectangle of 1 square by 2 (1x2). That can go 7 across and 8 down (or vice versa) so that is 8*7 times it fits in the 64 squares.

For the others:

1x3=6*8
1x4=5*8
1x5=4*8
1x6=3*8
1x7=2*8
1x8=1*8

2x3=6*7
2x4=5*7
2x5=4*7
2x6=3*7
2x7=2*7
2x8=1*7


3x4=5*6
3x5=4*6
3x6=3*6
3x7=2*6
3x8=1*6 ...[text shortened]... s for the rectangles going in one direction, for the other direction, multiply by 2 to get 1092.
Aren't squares rectangles?

1 edit
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OK. ok. ok

How many Polygons are there in total on a chessboard?

Edit: Stick it to science or debates, cos I don't have an answer!

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next time square root day happens it will be my 37th birthday.

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Originally posted by PocketKings
next time square root day happens it will be my 37th birthday.
Weird.

On the next square root day I will be hung over from my 37th birthday...

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