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jpearson311 02-18-2010 09:59 AM

How do I calculate this angle?
 
1 Attachment(s)
I have a 2x12 that I need to cut a 22.5 degree angle in. It has to start from 3-3/4" in from the top end, but how do I know how far I need to mark it down the side (see pic)? Thanks!

JP

47_47 02-18-2010 10:16 AM

I don't have a scientific calculator here, but to figure it out 3.75 multiplied by the tangent of 22.5 will give you the height. I drew it up and it is 1.553" or 1-9/16".

jlhaslip 02-18-2010 11:02 AM

A 5-12 pitch works out to 22.6195 degrees.

Is that close enough?

I calculate the length as 1 35/64ths.

jpearson311 02-18-2010 11:04 AM

Quote:

Originally Posted by jlhaslip (Post 402019)
A 5-12 pitch works out to 22.6195 degrees.

Is that close enough?

I calculate the length as 1 35/64ths.

Now that's what I'm talkin' about jlhaslip! Kick ass! Although, I don't think my tape measure has 35/64th marks. How do I mark it? Thanks!

JP

Thurman 02-18-2010 01:08 PM


s.w.a.g. ?

jpearson311 02-18-2010 01:09 PM

Quote:

Originally Posted by Thurman (Post 402097)

s.w.a.g. ?

What is that?

PaliBob 02-18-2010 01:31 PM

Quote:

Originally Posted by jpearson311 (Post 402099)
What is that?

http://www.acronymfinder.com/SWAG.html

jpearson311 02-18-2010 01:33 PM

Quote:

Originally Posted by palibob (Post 402110)

lolololololol!

baum 02-18-2010 01:37 PM

1.55330086" from the top. any more places you can figure it out.

6th grade math?? J/K

jpearson311 02-18-2010 01:38 PM

Quote:

Originally Posted by baum (Post 402113)
1.55330086" from the top. any more places you can figure it out.

6th grade math?? J/K

Thanks. It's been a while since I've worked with tangents. ;)

AllanJ 02-18-2010 01:48 PM

A regular corner is 90 degrees (a right angle). Divide it in half as if you were cutting a pizza or a cake. Divide each half in half* to get 22-1/2 degree slices. If you made a cardboard jig like this, would that help you measure?

Swag -- Refers to a light fixture hung from the ceiling where the power cord or cable is strung along the ceiling and then down the wall if needed to reach a receptacle.

* Easier to eyeball it equally compared with dividing the 90 degree angle into 4 parts all at once.

jpearson311 02-18-2010 01:49 PM

Quote:

Originally Posted by AllanJ (Post 402122)
A regular corner is 90 degrees. Divide it in half as if you were cutting a pizza or a cake. Divide each half in half to get 22-1/2 degree slivers. If you made a cardboard jig like this, would that help you measure?

Swag -- Refers to a light fixture hung from the ceiling where the power cord or cable is strung along the ceiling and then down the wall if needed to reach a receptacle.

Actually I just made a paper jig not cardboard. Thanks! I'm new to this forum, but everyone on here is so quick and helpful.

jlhaslip 02-18-2010 05:46 PM

S.cientific W.ild A.ss G.uess

tpolk 02-18-2010 06:11 PM

buy a protractor

Kevin M. 02-18-2010 06:33 PM

Buy a speed square. So easy a caveman can use it.!


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