# 3d trig problem (i think)

Hi

Not sure if this is simple or not but I can't figure out how to do it! I am designing a surround that will be constructed by folding a sheet of aluminum. I've got the geometry right in 3d but I want to transpose this to a template. Yes I can measure but I want to solve using maths for two reasons, one because i'm curious and can't do it and two, it will be more accurate.

One side is a mirror of the other, have just labelled for clarity. Distances A and C are the same when constructed (59). A I think will remain 59 but C I am not sure about? Distance B is unknown and what I would like to find, then I can just join a line between the two to obtain length C.

For the bottom triangles, distance D is known.

Let me know if other distances are needed and I will figure whether I know them or not?

Thanks

Will

## Answers and Replies

Can no one help on this? Am I missing some information?

mathman
Science Advisor
Your pictures are too unclear.

Thanks for the response. Stuff always clear in your own head! Now that I know they are not understandable, I try to make them clearer. I have attached some images that will hopefully make it clear. From a perspective viewpoint, this is what I want to end up with.

From the Side

And from the top

The angle (theta) in the side image has been calculated and is known. 7.6 deg.

I am making it out of a sheet of aluminum so I need to know dimensions in 2d so that they give me the desired shape in 2d. The 2d shape will be folded to give the 3d one.

In 2d, I don't know the angles phi and tau from this image.