Help calculating lengths after angle cuts

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Forum topic by Adrian A posted 08-31-2013 03:30 AM 1237 views 1 time favorited 4 replies Add to Favorites Watch
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Adrian A

169 posts in 3046 days

08-31-2013 03:30 AM

So if my piece is 1.5”wide then I cut an angle at the degrees shown how do I find out the length of ”?”

Also how bout if I do it backwards. If I know ”?” Is 1.5” how do I find out what the other is?

I don’t want to find out but trial and error or cut and check.

4 replies so far

View darinS's profile


713 posts in 3011 days

#1 posted 08-31-2013 03:52 AM

? = 3 inches

1.5 divided by the sine of 30 degrees.

If you know ?, then multiply it by the sine of 30 degrees.

Hope this makes sense. If not, shoot me a PM and I will try to explain it further.

-- They say many people die because of alcohol. They never realized how many of them are born because of it.

View Picklehead's profile


1043 posts in 2073 days

#2 posted 08-31-2013 10:59 AM

Google “sohcahtoa”. Oh no!!! I swore I would never use my 8th grade geometry!!!!!!!!

-- You've got to be smarter than the tree.

View jackthelab's profile


313 posts in 2837 days

#3 posted 08-31-2013 11:28 AM

Hey the simplest way is to draw the format out on a piece of cardboard and take the measurement.

-- Dave in Minnesota - If it ain't broke, improve it!

View MrFid's profile


884 posts in 2048 days

#4 posted 08-31-2013 12:12 PM

Automatically favorited and when I get to teaching this in geometry this year, you know I’m showing this to my class. Darin is correct, by the way. To do it backwards, switch 1.5 and ? in the equation I provided. I’ll leave the rest as homework.

-- Bailey F - Eastern Mass.

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