How Many Triangles?
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ren wrote: 64
Finally, someone agrees!
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MCSH wrote:
Akkarin wrote:
MCSH wrote:
Alexandre Orion wrote:
MCSH wrote: 56... and can prove it:D
THAT'S OUR SAJJAD !!!!!
... now, please show us.
Count those that have the bottom edge and the 2 other edges are equal (4)
Now we'll count those on left side and then multiply it by 2, (to cover those on right as well)
To count those on left, you can count those that their right edge is lowest line that comes from right, and then multiply it by 4.
They are:
3 small ones + 2 made of two small triangle + 1 made of 3 triangles + 3 that have bottom line (9)
Weird... it results in 76... I should've made a mistake in calculation last time![]()
My solution:
Warning: Spoiler!Only focusing on one side for a second:
Taking the line from bottomright to bottomleft, the lowest line on the left goes across to meet the line bottomright<->top. Using the lines that leave the bottomright point you can make 4 triangles that use that point.
Taking the point that intersects the lowest line from bottomright with the lowest line bottomleft, you can use the other lines bottomright<->top to make 3 triangles that use that point. (remembering that it is one less because there is one fewer line (the bottom one) being used)
Follow this for the other two points that intersect with the lowest line from bottomleft and you can make 2 triangles and then 1 triangle.
4+3+2+1=10
That can be done with each of the (4) lines leaving bottomleft point so you have 4x10=40 and that can be doubled by mirroring it on the other side so 2x40=80
At least I think that's right
You are counting those at center twiceso it's 4 more
My mistake, well spotted!
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Malcolm Serenity wrote:
ren wrote: 64
Finally, someone agrees!
What can I say? I don't like being wrong
did you think of them as dimensions or did you count ?
Convictions are more dangerous foes of truth than lies.
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ren wrote:
Malcolm Serenity wrote:
ren wrote: 64
Finally, someone agrees!
What can I say? I don't like being wrong
did you think of them as dimensions or did you count ?
Neither. There's actually a mathematical way to do it, and that's how I did it. It all depends on how many unique lines come out of the bottom vertices
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Convictions are more dangerous foes of truth than lies.
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ren wrote: that's what i call dimensions. I looked at it in a sort of distorted 3d space. Like a non-cubic 4x4x4 cube of sorts
Ahh. That makes sense!
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Malcolm Serenity wrote:
ren wrote: that's what i call dimensions. I looked at it in a sort of distorted 3d space. Like a non-cubic 4x4x4 cube of sorts
Ahh. That makes sense!
really? When I do stuff like this it makes me feel like I'm about to discover the solution to ftl or time travel

how did you go about it?
Convictions are more dangerous foes of truth than lies.
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ren wrote:
Malcolm Serenity wrote:
ren wrote: that's what i call dimensions. I looked at it in a sort of distorted 3d space. Like a non-cubic 4x4x4 cube of sorts
Ahh. That makes sense!
really? When I do stuff like this it makes me feel like I'm about to discover the solution to ftl or time travel
how did you go about it?
Hahaha. I did it based off a a simple equation. For any "How many triangles" that are set up in this same way (intersecting lines originating from 2 vertices), you take the number of unique lines that originate from one of the bottom vertices and cube it. Thus, if you count the unique lines in the left or right vertices, you get 4. Cube it, and you get 64.
If you take just a plain triangle, there is only one unique line from each of the vertices. Thus, you get 1 triangle.
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If you add a new line to each vertex, you will find that you can form 8.
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Thus, 3 unique is 27.
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And finally, 4 unique is 64
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- Wescli Wardest
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So I wrote down all the ones I could find. Or, I made a picture.
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Wescli Wardest wrote: I know the math, but I was having a herd time visualizing all the variables. (probably spent too much time at work)
So I wrote down all the ones I could find. Or, I made a picture.
Warning: Spoiler!
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Another excellent way of solving
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- Alethea Thompson
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∞
4. Challenge me, I'll prove it. LMAO!
Gather at the River,
Setanaoko Oceana
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Being silly of course... as the question is how many triangles occur in the prescribed pattern and I got to about 23 or 24 and then saw the other posts here with the answer. Oh thank you for saving me time
:silly:
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Sites with the answer.
Website:
http://scienceblogs.com/startswithabang/2012/07/28/weekend-diversion-triangles-a-puzzle-and-beauty/
Here is a youtube video of the count. It shows all the counting from left and right side then eliminates double counts.
http://www.youtube.com/watch?v=MUrkkoKbzWE Answer 64.
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