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# 45 degree angle

#1
06-26-05, 06:54 AM
teal310
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45 degree angle

howdy all ,I am at the cottage-the wife says she wants some corner shelves made- all I have is a hammer,handsaw, nails,lumber and a 12 inch ruler --how do I measure and mark the boards to cut a 45 degree angle??? thks. TEAL310

I moved your thread as the Tips and Tricks Forum is non-interactive Forum and no answers can be given there. MD.

Last edited by majakdragon; 06-26-05 at 01:23 PM. Reason: Moved thread
#2
06-26-05, 04:11 PM
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You've probably seen what a "miter box" looks like in stores. I'd make one large enough to cut your shelving, assuming that your saw is long enough to cut all the way across your shelves. If not, then you'd have to mark the diagonal and follow the line as you cut. (good luck)

Marking the 45 would just be a matter of measuring the width of the board, (say 10") then measuring 10" in from the end, and making a mark to represent the short point of the angle. Connect that mark with the corner of the board, and that should be your 45 degree angle.

#3
06-26-05, 07:49 PM
jluce
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I'm not sure there's enough information in your email to answer, but maybe this will be responsive. A 45 degree angle can be marked by carefully measuring the width of your shelf board and then measuring in from the end of the board the exact same measurement. Then, you draw a line from the corner of the board at the very end to the mark you made along the long axis of the board. That line will be a 45 degree cut.

#4
06-27-05, 01:02 AM
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You can also fold a piece of paper and use that as a guide to mark you boards.

#5
06-27-05, 07:42 AM
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hi
take your board with and mark it and draw a diagonal line to each end you have 45 degree

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#6
09-20-07, 07:29 PM
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Use some trigonometry :)

Figure out the depth you want the shelf coming out from the corner...

draw your shelf on a piece of paper (a right angle)

draw a line coming from the corner to the face of the shelf (your depth, label it)

you will have 2 triangles now.

find your Adjacent, Opposite and Hypotenuse sides of one of the two triangles.

you have (2) 45 degree angles and a 90 degree angle...

use Tangent to fine the length of the OPPOSITE side

Tan of 45 degrees = Opposite / Adjacent

1 = Opposite / 10" ... solve for X now (opposite)

to get opposite by itself, multiply by 10 on both sides of the equation, you end up with...

1 X 10 = Opposite

or...

1 X 10 = 10"

so now you know that the opposite side of the small triangle is 10, now use pthatgoram's theorem to find the hypotenuse of the small triangle (which is the OPPOSITE side of the whole shelf, which is also the length the shelf will be against one of the walls)

A squared + B squared = C squared (C is always the hypotenuse)

you get --> 100 + 100 = 200 squared

take the square root of 200, you get 14.14 inches

so you get the hypotenuse of the small triangle as 14.14, which also happens to be the opposite side of the whole big triangle, or shelf.

so now what you have is 14.14 inches for 1 side against a wall, and you have a total hypotenuse of 20 inches. since you want the shelf to be centered then you automatically know that the other side of the shelf against the wall will also be 14.14 inches. you can check this with the theorem again..

14.14 squared + 14.14 squared = 399.88 squared

square root of 399.88 = 19.996 inches (which is close enough to 20 inches, your hypotenuse)

voila..

Jeff

#7
09-21-07, 05:45 AM
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Re previous post:

See post #2

K.I.S.S.

#8
09-22-07, 02:15 AM
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So you have a computer with internet access at your cottage? Something's wrong with that..... And you have all that, but there's no hardware store nearby to buy a cheap framing square?????

skij710 must be an engineer. Sometimes overthinking is just plain stupid

#9
09-22-07, 03:07 AM
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Well what do you expect- he's been working on that answer for 2 years 3 months.

#10
09-22-07, 11:16 PM
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No wonder why I never got any answers from engineering departments. They're still working on them!

It's all in good fun to my engineering friends out there.

#11
07-02-09, 12:07 AM
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Marking the 45 would just be a matter of measuring the width of the board, (say 10") then measuring 10" in from the end, and making a mark to represent the short point of the angle. Connect that mark with the corner of the board, and that should be your 45 degree angle.[/QUOTE]

So you're saying if I had rectangular blocks 3/8" wide and 3" long, all I have to do is measure down 3/8" from the ends, make a square and bisect it.
How far down would I need to measure for an equalateral triangle or for a hexagon?

#12
07-02-09, 05:22 AM
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Polygons

101101,

Draw a triangle with 3 equal sides and it will be an equilateral triangle. Draw a circle and use the radius to divide the circle into 6 equal segments. Join adjacent segment marks with straight lines and you have a hexagon.

#13
07-02-09, 11:41 PM
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didn't ask how to draw a hexagon, asked how to cut angles into six blocks of wood to make them into a hexagon.

#14
07-03-09, 11:57 AM
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Hexagon

60 deg., 60 deg., 60 deg.

#15
07-03-09, 02:49 PM
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How far down would I need to measure QUOTE]

#16
07-04-09, 04:37 AM
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Question

Please restate your question with more detail; how far down from what?

#17
07-08-09, 11:51 PM
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All necessary info has been provided, including measurements in inches.

#18
07-23-09, 01:21 PM
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cutting a 45

You guys are sure making this hard. Jam one shelf board in the corner with its edge along one wall. bring the other board in from the other wall,laying on top of the first one. Mark both boards along the edge of the other, then make a diagonal from the mark to the end of the board. This will fit when the corner isnt square which most arent.

#19
07-29-09, 05:46 AM
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Well, that helps the guy who posted four years ago.

Can anyone help with my question of how to cut angles* without a miter box, or anything more than a ruler?

*I have six blocks of wood(3/8" wide). I'd like to cut them so that when laid end-to-end they form a hexagon.

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