2d geometry problem .... ?
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2d geometry problem .... ?
Figure A:
Given the coordinates of A, B, and C and some arbitrary point within the triangle P ...
Figure B:
... and given some arbitrary angle a, how can I work out the distance d to the boundary of the triangle?
Cheers in advance
===================================================
Given the coordinates of A, B, and C and some arbitrary point within the triangle P ...
Figure B:
... and given some arbitrary angle a, how can I work out the distance d to the boundary of the triangle?
Cheers in advance
===================================================
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Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Re: 2d geometry problem .... ?
Fixed the attachment issue above. So the problem is calculating the distance to the boundary of a triangle from any point within it it, in any direction, when the points of the triangle are three sets of {x, y} 2d coordinates relative to top-left {0, 0}.
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There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Details on how to do that can be found here.
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Re: 2d geometry problem .... ?
I don't think you can.
Yeah well that's just, like, your opinion, man.
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Re: 2d geometry problem .... ?
Bum.
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Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Details on how to do that can be found here.
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Re: 2d geometry problem .... ?
I was hoping there'd be some kind of formula, but perhaps I need to break it down into smaller triangles or something.
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Details on how to do that can be found here.
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"It isn't necessary to imagine the world ending in fire or ice.
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Re: 2d geometry problem .... ?
Surely I haven't stumbled upon an unsolvable Trigonometry problem?
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There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Details on how to do that can be found here.
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
Frank Zappa
"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
Re: 2d geometry problem .... ?
Connect the dot to all three corners. That creates three triangles. The height of these triangles is the distance of the point to the borders.
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Re: 2d geometry problem .... ?
it's not a trig problem. to calculate a distance, you need measurements. If you knew the length of the sides of the triangle, and the point's distance to the other two sides, you might have a prayer of doing it, but in a triangle of indeterminate size and with an undefined point, calculating a distance is impossible.
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Re: 2d geometry problem .... ?
Rubbish. You do that in 7th grade at schoolSvartalf wrote: ↑Tue Mar 10, 2020 6:53 pmit's not a trig problem. to calculate a distance, you need measurements. If you knew the length of the sides of the triangle, and the point's distance to the other two sides, you might have a prayer of doing it, but in a triangle of indeterminate size and with an undefined point, calculating a distance is impossible.
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Re: 2d geometry problem .... ?
You can get the lengths of the big triangle legs because you're got the coordinates. With all three legs you can get the internal angles. But that's still not solving the problem. To do that you'd need either the coordinates where two legs of the cross intersect the big triangle, or 2 angles and one length on the smaller triangle to calculate d. The smaller triangle has one 90 angle, and one equal to 360 -(a + 90). But you still need a length.
You could move point P anywhere within the big triangle and angle a would remain the same, but d would change.
You could move point P anywhere within the big triangle and angle a would remain the same, but d would change.
Yeah well that's just, like, your opinion, man.
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Re: 2d geometry problem .... ?
The figure may be misleading. The angle a is arbitrary, therefore h = 2A/b only guarantees d = h when a is a specific value - imagine how it'd look with a ± 20°
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Details on how to do that can be found here.
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
Frank Zappa
"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Re: 2d geometry problem .... ?
I think I need this explained in a simpler form that the Wiki page offers.
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
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"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Details on how to do that can be found here.
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"It isn't necessary to imagine the world ending in fire or ice.
There are two other possibilities: one is paperwork, and the other is nostalgia."
Frank Zappa
"This is how humanity ends; bickering over the irrelevant."
Clinton Huxley » 21 Jun 2012 » 14:10:36 GMT
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Re: 2d geometry problem .... ?
9B has nailed it. You actually don't need the angle you mentioned in your OP, Brian, simply all 4 coordinates, then use 3 different versions of the formula, one for the perpendicular distance to each of the 3 sides. You could, additionally, calculate the angle if you wanted.
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