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convert degrees, minutes, and seconds into feet

PostPosted: Wed Apr 26, 2006 11:35 pm
by david364
How do you convert from degrees, minutes, and seconds into feet and inches?

PostPosted: Thu Apr 27, 2006 1:07 am
by Phil57
I know this one...

I presume you are measuring the length of an arc or curve between two points. You need to know the radius or the arc you are trying to measure the length of.

then it just a case of using this formula:

L = (A / 360) x (2 x pi x r)
where L-Length, A=Angle, pi=3.14..., r=radius of the circle.

Also, there are 60seconds in a minute and 60minutes in a degree (360sec in a degress). And 1 foot = 12inches, and approx 0.0394mm in one inch.

Its probably easier to work in metric (ie mm or meters) to be honest. Find the radius in mm, calculate the arc length L in mm, convert into inches, then divide by 12 for the number of whole feet, then simply multiply the decimal remainder by 12 for the number of remainder inches.

Hope this helps.

Re: convert degrees, minutes, and seconds into feet

PostPosted: Thu Sep 02, 2010 10:13 pm
by suzanneo
Bending Metal.
3" height by 1.5" Length with a 3/4" angle
What is the degree of the bend?

Re: convert degrees, minutes, and seconds into feet

PostPosted: Thu Sep 09, 2010 10:23 pm
by Dirtman
suzanneo wrote:Bending Metal.
3" height by 1.5" Length with a 3/4" angle
What is the degree of the bend?


The angle (Theta) is 28.9550 decimal degrees, measured by the chord length of 3/4” (point on arc to point on arc), which forms an Isosceles triangle.

The formula is: Theta = arcsine (0.5 * opposite side / hypotenuse)) * 2, so:

Theta = arcsine (0.5 * 0.75” /1.5”)) * 2;
Theta = arcsine (0.375 /1.5)) * 2;
Theta = arcsine (0.25)) * 2;
Theta = 14.477512 * 2;
Theta = 28.9550º or in DMS format: 28º 57’ 18”