Field measuring question

[daniels123]

Hello,
I do a lot of field measuring for a company and on this newest job I've been measuring a lot of area outside of radii. Picture a 90 degree triangle with one edge curved into the triangle. I've been figuring out the radius of the circle and subtracting that from the triangle area. Is there an easier way to measure this to get a fast area? It does not have to be 100% exact.

Thanks

 

[IRstuff]

" It does not have to be 100% exact" by how much?

A cheesy solution would be to treat the missing area as a triangle

TTFN

FAQ731-376

 

[Hoagie]

Plot the shapes in Autocad, then bpoly the subject region; then list the area of the bpoly for a precise area determination.

 

[IRstuff]

A more rigorous and even possibly halfway accurate approach is to digitize the curve and do a straight-forward numerical integration.

TTFN

FAQ731-376

 

[CarlB]

What information do you have on the curved side, do you know the radius or do you have a height & have to calculate/estimate the radius?

If radius is know, use a formula for a segment and subtract from triangle (this may be what you are doing..)

For central angle in degrees
A=R^2/2(CxPI/180 -sinC)

where:
C is the central angle in DEGREES
R is the radius of the circle of which the segment is a part.
sin is the trigonometry Sine function.

 

[beej67]

I would build a spreadsheet for this and stick it on my iPhone.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[underhill]

Do you have the bearing and distance of each straight side and the beginning of curve radial bearing and distance plus either the end of curve radial B&D or the delta (deflection) angle? If so, you can easily get the exact area using good cogo software. Copan, by UGL, is a free example of same.