mansan
asked on
Center point of arc
I've one more question please.
There is an arc having 11 x,y points. How to calculate coordinates of center of this arc?
Thanks.
There is an arc having 11 x,y points. How to calculate coordinates of center of this arc?
Thanks.
ASKER CERTIFIED SOLUTION
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..and you shouldmake sure all pairs result in the same centerpoint
Sorry, that ain't right.
Given any two points, there are an infinite number of different arcs that pass through both.
You can see this because if you do what kartik suggested, you get:
(x-x1)^2+(y-y1)^2=(x-x2)^2 +(y-y2)^2
1 equation with 2 unknowns (x and y) has an infinite number of solutions.
So you need *three* points, from which you can get *two* equations:
(x-x1)^2+(y-y1)^2=(x-x2)^2 +(y-y2)^2
and
(x-x1)^2+(y-y1)^2=(x-x3)^2 +(y-y3)^2
and now you really can solve for x and y.
kotan answered the question `how do I find the center of mass of the arc' rather than `how do I find the center of the circle of which the arc belongs to' .. if that was what you intended, then his answer is correct.
Given any two points, there are an infinite number of different arcs that pass through both.
You can see this because if you do what kartik suggested, you get:
(x-x1)^2+(y-y1)^2=(x-x2)^2
1 equation with 2 unknowns (x and y) has an infinite number of solutions.
So you need *three* points, from which you can get *two* equations:
(x-x1)^2+(y-y1)^2=(x-x2)^2
and
(x-x1)^2+(y-y1)^2=(x-x3)^2
and now you really can solve for x and y.
kotan answered the question `how do I find the center of mass of the arc' rather than `how do I find the center of the circle of which the arc belongs to' .. if that was what you intended, then his answer is correct.
ASKER
Thanks you all for kind help.
Let (x1,y1) and (x2,y2) be two of the points on arc.
Then :
(x-x1)^2+(y-y1)^2=r^2 where r is the radius.
(x-x2)^2+(y-y2)^2=r^2
So equate these two equations to get the centre of circle which (x,y)
With regards,
V.Kartik