Coding after hitting the all-you-can-eat chinese buffet is not a good idea. Food coma, mixed with already dimwitted-ness, is not a good combo. I am supposed to be programming an estimator for calculating the surface area of a log home. Plain surface area is simple length x width. Surface area for a cylinder is (2 pi r)* h (where "h" is the length, or height, of the cylinder). But what if I only need to figure part of the cylinder? Any ideas? See below:



Compounding the issue is that we have "super round" and "rounded" logs. Super round have a greater arc than rounded. At the present I don't have the exact figures.

In the sketch you posted, the arc length is about 10 inches. You need to provide some more information, e.g. the angle of the arch, or the chord of the arch, or the length of the contact surface cut.

Here's some math to calculate the arc if you know the angle
http://www.math-prof.com/Geom/Geom_Ch_32.asp

The way I figure it's roughly about 114 degrees in the example above. So if d=10, and the arc is 114/360, then yep the d*p*.316666 is just about 10.


Thanks voks!

Considering the nature of your business, I would venture a guess that the number you need to work with is the height of the cut log (i.e. the chord), which will be some set number, so that all stacked logs end being the same height.

YOU GUYS ARE HURTING MY BRAIN!!!!! Sorry Tofu, wish I could help....

Just wait until I ask for help figuring out the linneal feet of the joints for estimating caulking needed.

Here's an online calculator, input two known numbers (e.g. radius and chord) and get the rest
http://www.handymath.com/cgi-bin/arc18.cgi?submit=Entry

Here's another one
http://www.1728.org/circsect.htm

Keep talking. I think I'm getting a chubbie.

Simple solution

Guess

works for me most of the time

Choose "C"

Final answer!

Wow, rein! You bring a fresh perspective to this picture.