help with measurements?

[Melissa]

If anyone can help with these measurements, something just seems off, I'm terrible at geometry, but can measure and cut just fine.

I'm wanting to build a corner cabinet for my tv and related equipment. The design size is limited on one side to 34" because of a door jamb. The shape I've come up with is 5 sided-essentially the same as a profile of a diamond from a ring-not a pentagon. Measurements of 22" for the front (tv screen edge), 12" each side, then 34" for each of the back sides. I've just cut out graph paper, one square to one inch to fit these measurements. The TV itself is box shaped, narrowing slightly towards the back. 25" across the front screen edge, 19" deep, and 19" wide at the back. I've also cut the graph paper to fit those measurements. The tv paper fits well inside the cabinet paper, but it doesn't seem like it should. Given that the cabinet paper front edge is only 22 squares (cut on the diagonal) and tv paper is

25 squares wide, how is this possible. Have I measured wrong, is it a matter of perception, something else? I don't want to buy and cut wood if this just isn't going to work.

Thanks!

[Bay Area Dave]

sounds like a simple math problem. YOU and the rest of us that have half a brain know that the diagonal of a square is longer than a side...

think "a" squared plus "b" squared equals "c" squared... a and b are sides and c is the diagonal. I'll let YOU do the rest.

dave

Melissa wrote:

[jim]

A pentagon is a Five Sided figure, a diamond can be any shape?????

[Jim Wilson]

I'm not sure you have the sizes you think you do. 22 diagonals would be just under 31-1/8". A square's diagonal is about 1.414 times the length of a side. That would account for your TV model fitting in the space, but then you'd have the wrong measurements for the plan view of the cabinet. Are all the angles right angles? If so, then all your measurements given above work except the front, which is actually 31.110".

Cheers!

Jim

[Melissa]

Thanks Dave, that's exactly the problem. As I said, I'm terrible at geometry, so bad that I didn't realize the diagonal was longer than the sides. I guess my half brain isn't the half that can handle that. :) All set now, just needed a bit of reassurance that the tv would indeed fit. Thanks!

[Melissa]

[Melissa]

My information was off. I gave measurements for all but the front edge, that I gave in squares. I made the other measurements on the wall itself, but couldn't make the diagonal measurement (couldn't get the m. tape to steady enough for that), so was going on the incorrect assumption that the diagonal of the square was the same as the length of a side. Corrected now, thanks!

[TinWoodsmn]

Your mistake is assuming the diagonals of the graph paper are 1". They are actually 1.414".

Draw two 34" lines at 90 deg to each other. At the end of these lines draw a

12" radius circle. Connect the circle centers. Cut a piece of graph paper to 22" and carefully place it between the circles so that simultaneously the ends touch the circles and the paper is parallel to the line joining the centers. Mark on the circles where the graph paper has touched. Draw lines from these points to the circle centers. You have your five sided diamond. Angles can be read with a protractor.

Good luck.

TW

[Jim Wilson]

Except in this case, a 22" segment cannot touch both circles, because they are over 24" apart at the closest.

Jim

[Bay Area Dave]

Cool!

dave

Melissa wrote:

[TinWoodsmn]

Jim, you're absolutely right. I should have checked my work more closely before sending a non solution.

Happy New Year to all.

TW

[Bruce]

I've tried to draw this in AutoCAD and I get the idea but it won't work with the measurements you gave me unless the 2 34" sides aren't perpendicular. Are they? If so, the 22" will never meet the 12" sides.

[Bruce]

I'm not able to reproduce a design like that in AutoCAD. Are the 2 34" pieces at a right angle? That is what I assumed since it is in a corner. If they are, the geometry doesn't work. The 22" front will never intersect

12" sides.

[Bay Area Dave]

talk about overkill! her question has already been answered, without the need for Autocad...sigh...

dave

Bruce wrote:

[Bruce]

Actually, those weren't supposed to be sent because I'd seen it was already answered. As for AutoCAD, I do everything in AutoCAD and hardly consider it overkill. I drew it up in about 3 minutes, much easier than sketching it on paper.

[Dave Balderstone]

Instead of messing with all the math, why don't you just use a story stick?

djb

[Tom Baker]

The diagonal front face of the box is 31.11"

Tom Baker

[Jim Wilson]

No sweat, mon. I had asked Melissa if all the angles were right angles. Hello-oh! The polygon has five angles; they can't *all* be right! (G)

To you, too!

Jim

[Bay Area Dave]

I'm not saying anything's wrong with using Autocad, Bruce; just that the OP's question was of a basic nature, needing a simple answer regarding diagonals.

dave

Bruce wrote:

[Bruce]

Dave,

I drew it out to determine what her problem was. I had no idea she was equating the hypotenuse of a square with the side of a square because I found her description hard to follow. I'm much more visual. Once I saw the picture, the light went on.