Calculate coordinates of third point in a triangle (2D) knowing 2 points coordinates [closed]
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Triangle
I have 2 points v1 and v2. I have a length B. I can work out length A and therefore C if necessary. My aim is to find the coordinates of v3. I have tried a few different ideas but can't get the correct solution. Any ideas? Thank you.
Solution1
triangles
edited Dec 14 '18 at 19:42
Namaste
1
asked Dec 14 '18 at 19:29
iainiain
32
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closed as unclear what you're asking by Namaste, user10354138, Paul Frost, Leucippus, Cesareo Dec 15 '18 at 0:58
Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
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$begingroup$
Triangle
I have 2 points v1 and v2. I have a length B. I can work out length A and therefore C if necessary. My aim is to find the coordinates of v3. I have tried a few different ideas but can't get the correct solution. Any ideas? Thank you.
Solution1
triangles
edited Dec 14 '18 at 19:42
Namaste
1
asked Dec 14 '18 at 19:29
iainiain
32
$endgroup$
closed as unclear what you're asking by Namaste, user10354138, Paul Frost, Leucippus, Cesareo Dec 15 '18 at 0:58
Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
add a comment |
$begingroup$
Triangle
I have 2 points v1 and v2. I have a length B. I can work out length A and therefore C if necessary. My aim is to find the coordinates of v3. I have tried a few different ideas but can't get the correct solution. Any ideas? Thank you.
Solution1
triangles
edited Dec 14 '18 at 19:42
Namaste
1
asked Dec 14 '18 at 19:29
iainiain
32
$endgroup$
Triangle
I have 2 points v1 and v2. I have a length B. I can work out length A and therefore C if necessary. My aim is to find the coordinates of v3. I have tried a few different ideas but can't get the correct solution. Any ideas? Thank you.
Solution1
triangles
triangles
edited Dec 14 '18 at 19:42
Namaste
1
asked Dec 14 '18 at 19:29
iainiain
32
edited Dec 14 '18 at 19:42
Namaste
1
asked Dec 14 '18 at 19:29
iainiain
32
edited Dec 14 '18 at 19:42
Namaste
1
edited Dec 14 '18 at 19:42
Namaste
1
edited Dec 14 '18 at 19:42
Namaste
1
1
asked Dec 14 '18 at 19:29
iainiain
32
asked Dec 14 '18 at 19:29
iainiain
32
asked Dec 14 '18 at 19:29
iainiain
32
32
closed as unclear what you're asking by Namaste, user10354138, Paul Frost, Leucippus, Cesareo Dec 15 '18 at 0:58
Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
closed as unclear what you're asking by Namaste, user10354138, Paul Frost, Leucippus, Cesareo Dec 15 '18 at 0:58
Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
add a comment |
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2 Answers
2
active
oldest
votes
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Your solution is almost correct, except the definitions of $T$ and $Q$ (they should be the other way around). This is because alpha is the angle between the vertical and $B$. To check, use $V_1=(0,0)$ and $V_2=(3,0)$. The final coordinates have to be $(3,3)$. From programming point of view, use np.atan2 instead. Then you don't need to calculate $A$. Also, note that you can go in the other direction as well ($V_3$ could be the other side of the $V_1 V_2$ line)
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
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Thank you, that should work.
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– iain
Dec 14 '18 at 20:10
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The unit vector parallel to edge $v_1v_2$ is given by $displaystylehat n=frac{vec v_2-vec v_1}{|vec v_2-vec v_1|}=(alpha,beta)$. The direction ratios of the unit vector perpendicular to $hat n$ is given by $hat m=(pmbeta,mpalpha)$. The position vector of vertex $v_3,vec v_3=vec v_2+Bhat m$. Note that there are two answers for $vec v_3$.
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
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add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Your solution is almost correct, except the definitions of $T$ and $Q$ (they should be the other way around). This is because alpha is the angle between the vertical and $B$. To check, use $V_1=(0,0)$ and $V_2=(3,0)$. The final coordinates have to be $(3,3)$. From programming point of view, use np.atan2 instead. Then you don't need to calculate $A$. Also, note that you can go in the other direction as well ($V_3$ could be the other side of the $V_1 V_2$ line)
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
$endgroup$
$begingroup$
Thank you, that should work.
$endgroup$
– iain
Dec 14 '18 at 20:10
add a comment |
$begingroup$
Your solution is almost correct, except the definitions of $T$ and $Q$ (they should be the other way around). This is because alpha is the angle between the vertical and $B$. To check, use $V_1=(0,0)$ and $V_2=(3,0)$. The final coordinates have to be $(3,3)$. From programming point of view, use np.atan2 instead. Then you don't need to calculate $A$. Also, note that you can go in the other direction as well ($V_3$ could be the other side of the $V_1 V_2$ line)
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
$endgroup$
$begingroup$
Thank you, that should work.
$endgroup$
– iain
Dec 14 '18 at 20:10
add a comment |
$begingroup$
Your solution is almost correct, except the definitions of $T$ and $Q$ (they should be the other way around). This is because alpha is the angle between the vertical and $B$. To check, use $V_1=(0,0)$ and $V_2=(3,0)$. The final coordinates have to be $(3,3)$. From programming point of view, use np.atan2 instead. Then you don't need to calculate $A$. Also, note that you can go in the other direction as well ($V_3$ could be the other side of the $V_1 V_2$ line)
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
$endgroup$
Your solution is almost correct, except the definitions of $T$ and $Q$ (they should be the other way around). This is because alpha is the angle between the vertical and $B$. To check, use $V_1=(0,0)$ and $V_2=(3,0)$. The final coordinates have to be $(3,3)$. From programming point of view, use np.atan2 instead. Then you don't need to calculate $A$. Also, note that you can go in the other direction as well ($V_3$ could be the other side of the $V_1 V_2$ line)
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
answered Dec 14 '18 at 19:47
AndreiAndrei
13.7k21230
13.7k21230
$begingroup$
Thank you, that should work.
$endgroup$
– iain
Dec 14 '18 at 20:10
add a comment |
$begingroup$
Thank you, that should work.
$endgroup$
– iain
Dec 14 '18 at 20:10
$begingroup$
Thank you, that should work.
$endgroup$
– iain
Dec 14 '18 at 20:10
$begingroup$
Thank you, that should work.
$endgroup$
– iain
Dec 14 '18 at 20:10
add a comment |
$begingroup$
The unit vector parallel to edge $v_1v_2$ is given by $displaystylehat n=frac{vec v_2-vec v_1}{|vec v_2-vec v_1|}=(alpha,beta)$. The direction ratios of the unit vector perpendicular to $hat n$ is given by $hat m=(pmbeta,mpalpha)$. The position vector of vertex $v_3,vec v_3=vec v_2+Bhat m$. Note that there are two answers for $vec v_3$.
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
$endgroup$
add a comment |
$begingroup$
The unit vector parallel to edge $v_1v_2$ is given by $displaystylehat n=frac{vec v_2-vec v_1}{|vec v_2-vec v_1|}=(alpha,beta)$. The direction ratios of the unit vector perpendicular to $hat n$ is given by $hat m=(pmbeta,mpalpha)$. The position vector of vertex $v_3,vec v_3=vec v_2+Bhat m$. Note that there are two answers for $vec v_3$.
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
$endgroup$
add a comment |
$begingroup$
The unit vector parallel to edge $v_1v_2$ is given by $displaystylehat n=frac{vec v_2-vec v_1}{|vec v_2-vec v_1|}=(alpha,beta)$. The direction ratios of the unit vector perpendicular to $hat n$ is given by $hat m=(pmbeta,mpalpha)$. The position vector of vertex $v_3,vec v_3=vec v_2+Bhat m$. Note that there are two answers for $vec v_3$.
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
$endgroup$
The unit vector parallel to edge $v_1v_2$ is given by $displaystylehat n=frac{vec v_2-vec v_1}{|vec v_2-vec v_1|}=(alpha,beta)$. The direction ratios of the unit vector perpendicular to $hat n$ is given by $hat m=(pmbeta,mpalpha)$. The position vector of vertex $v_3,vec v_3=vec v_2+Bhat m$. Note that there are two answers for $vec v_3$.
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
answered Dec 14 '18 at 19:39
Shubham JohriShubham Johri
5,558818
5,558818
add a comment |
add a comment |
