Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Related Articles


Field measuring question

Field measuring question

Field measuring question

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.


RE: Field measuring question

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

RE: Field measuring question

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


FAQ731-376: Eng-Tips.com Forum Policies

RE: Field measuring question

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)

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.

RE: Field measuring question

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

RE: Field measuring question

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.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close