How to calculate length of arc?

[BrandonDouglas]

How to calculate length of arc? Please Help!

First of all, Hi, I'm Brandon! :) 18 Years old currently doing A Levels - Uni End of this year!

(Not Homework - Coursework!)
So I have this design of a speaker system for my Product Design course in A-Level.
There are 3 arcs in my design that I need to know the length of for when my school orders the materials to my specific measurements.

Here is a picture with measurements of my design from SolidWorks CAD Software.

The arc at the top is 100mm high and the side arcs would be 50mm
All measurements in mm. I hope this is enough info for you to help me!

 

[jbriggs444]

So you know the radius of a circular arc and you know the length of a chord of that arc.

Can you draw a right triangle anywhere?

 

[jedishrfu]

does solidworks cad have a function to tell you the length by selecting the arcs of interest?

THis link seems to imply that:

http://grabcad.com/questions/how-to-dimension-arc-length-on-solidworks-drawing

and here at solidworks cad site:

https://forum.solidworks.com/thread/60322

 

[BrandonDouglas]

Thank you Jed! - I thought it must have a feature to do so! - hence why I added that I had used it.

Thank you very much guys, sorted!

 

[CellCoree]

Hi Brandon,

To calculate the length of an arc, you will need to know the radius of the circle that the arc is a part of and the angle of the arc in degrees. The formula for calculating the length of an arc is:

Arc length = (angle/360) x 2πr

In your case, the radius of the top arc is 100mm and the angle is 180 degrees (since it is a semi-circle). Therefore, the length of the top arc would be:

Arc length = (180/360) x 2π(100) = 100π ≈ 314.16mm

For the side arcs, you will need to measure the angle of the arc in degrees. Let's assume it is 90 degrees for this example. The length of the side arc would be:

Arc length = (90/360) x 2π(50) = 50π/2 ≈ 78.54mm

I hope this helps you in calculating the length of your arcs for your speaker system design. Good luck with your coursework!