DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Carpentry (http://www.diychatroom.com/f14/)
-   -   How do I calculate this angle? (http://www.diychatroom.com/f14/how-do-i-calculate-angle-64778/)

 jpearson311 02-18-2010 08:59 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 09:16 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 10:02 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 10:04 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 12:08 PM

s.w.a.g. ?

 jpearson311 02-18-2010 12:09 PM

Quote:
 Originally Posted by Thurman (Post 402097) s.w.a.g. ?
What is that?

 PaliBob 02-18-2010 12:31 PM

Quote:
 Originally Posted by jpearson311 (Post 402099) What is that?
http://www.acronymfinder.com/SWAG.html

 jpearson311 02-18-2010 12:33 PM

Quote:
 Originally Posted by palibob (Post 402110) http://www.acronymfinder.com/swag.html
lolololololol!

 baum 02-18-2010 12:37 PM

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

 jpearson311 02-18-2010 12:38 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 12:48 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 12:49 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 04:46 PM

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

 tpolk 02-18-2010 05:11 PM

 Kevin M. 02-18-2010 05:33 PM

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

All times are GMT -5. The time now is 08:52 AM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.