Need a little math help

[BigToque]

image.gif

I need to find the length of line AB and line CD. How would I go about finding it?

The image is horribly done, but it is supposed to be symmetrical

Oh, and point B is not the center of the circle.


Edit:

I updated the image with the information I know. If there is anything obvious I missed you can tell me and I'll add it.

 

[jhayx7]

Use a ruler?

 

[sash1]

Originally posted by: jhayx7
Use a ruler?

yeah, that's about all you can do with that information.

no angle, no fvckin' units even.

 

[BigToque]

Originally posted by: sash1

Originally posted by: jhayx7
Use a ruler?

yeah, that's about all you can do with that information.

no angle, no fvckin' units even.

I'm asking what information I would need to calculate the distance. If you can tell me what I need, I can do the rest. I just don't know what I need.

 

[snoopdoug1]

Originally posted by: BigToque

Originally posted by: sash1

Originally posted by: jhayx7
Use a ruler?

yeah, that's about all you can do with that information.

no angle, no fvckin' units even.

I'm asking what information I would need to calculate the distance. If you can tell me what I need, I can do the rest. I just don't know what I need.

you need to do it yourself. :evil:

 

[DaShen]

that is difficult. I haven't touched that type of math in 7-8 years.

 

[TuxDave]

Without any additional information, you can't solve it.

 

[Kyteland]

Is that supposed to be an inscribed square or a rectangle?

 

[nycxandy]

Originally posted by: TuxDave
Without any additional information, you can't solve it.

Yeah, it can't be solved.

 

[brikis98]

are there some options? i mean, there's many diff ways to get this... for example, if you have a right triangle and have the measure of one side and one angle, you can use trig identities to get the other sides (sin = opp/hyp, cos = adj/hyp, tan=opp/adj, etc)... so we need more info or you have to tell us what info we can request...

 

[SophalotJack]

Originally posted by: snoopdoug1

Originally posted by: BigToque

Originally posted by: sash1

Originally posted by: jhayx7
Use a ruler?

yeah, that's about all you can do with that information.

no angle, no fvckin' units even.

I'm asking what information I would need to calculate the distance. If you can tell me what I need, I can do the rest. I just don't know what I need.

you need to do it yourself. :evil:

you need the radius length and any of the angles that is the trianlgle is a part of (besides the part that touches the circle).

If you have that, you can solve is with trig equalities and such.

 

[BigToque]

I updated the image with the information I know. If there is anything obvious I missed you can tell me and I'll add it.

 

[BigToque]

anyone?

 

[chuckywang]

Originally posted by: sash1

Originally posted by: jhayx7
Use a ruler?

yeah, that's about all you can do with that information.

no angle, no fvckin' units even.

All you need is one more angle.

 

[Hyperion042]

It IS solvable with current information.

Define a 90 degree arc of the circle with one leg of it passing through B and the other leg parallel to CD. Then each side is 24" long, and you cut in half the distance along that long hunk of circle. Then using assorted trig identities and direct computation based upon the fact that the two sides of your 90 degree wedge are both 24", you can solve for AB and CD uniquely.

An easier way to work it is to do what I just said, but define the top left as the origin (0,0) in a euclidian coordinate system. Then the vertices of the wedge are at (24,0) and (0,-24), and you can solve for the locations of all the other points by enforcing information you have about the distances. From there you just measure the euclidian norm between A and B, C and D. Not a hard problem, but computationally intensive.

 

[chuckywang]

Originally posted by: Hyperion042
It IS solvable with current information.

Define a 90 degree arc of the circle with one leg of it passing through B and the other leg parallel to CD. Then each side is 24" long, and you cut in half the distance along that long hunk of circle. Then using assorted trig identities and direct computation based upon the fact that the two sides of your 90 degree wedge are both 24", you can solve for AB and CD uniquely.

An easier way to work it is to do what I just said, but define the top left as the origin (0,0) in a euclidian coordinate system. Then the vertices of the wedge are at (24,0) and (0,-24), and you can solve for the locations of all the other points by enforcing information you have about the distances. From there you just measure the euclidian norm between A and B, C and D. Not a hard problem, but computationally intensive.

I don't think it is. Look at the figure and imagine the angle at point B either being larger or smaller. The rest of the information does not change, but the values of AB and CD do change.

In short, you need to know the angle at point B to solve the problem.

 

[darthsidious]

I agree, you need to know some more info, preferably the angle at B.