Why is the circumference-to-diameter ratio constant in circles?

[Drakkith]

yes .14159 and so on .
please can you explain ?

What exactly do you want explained? Have you understood anything that's been said in this thread so far?

 

[akashpandey]

I understand what has been said in forum so far.now I also a dout that is
https://www.physicsforums.com/attac...1/?temp_hash=586afacbbfb47e99be368397d4138bd7.
what is exact measurement of that last part since the measurement of that last part is .142 so on is infinite so its length is also .142 and so on

 

[Drakkith]

what is exact measurement of that last part since the measurement of that last part is .142 so on is infinite so its length is also .142 and so on

The exact length is three less than pi: π-3 = 0.14159...

 

[akashpandey]

but how the length .142 is exact??

 

[akashpandey]

means .142...

 

[Drakkith]

but how the length .142 is exact??

How isn't it?

 

[Drakkith]

but how the length .142 is exact??

How isn't it?

To clarify, I'm asking so that I understand your thinking and level of knowledge on this.

 

[HallsofIvy]

https://www.physicsforums.com/attac...1/?temp_hash=586afacbbfb47e99be368397d4138bd7.
can somebody explain me the measurement of last part of the circle i.e .3142 and so on.
means what is the exact measurement of that last part?

All I see in your picture is a circle with the diameter marked (but numerical value given) and a small section marked off, labeled ".14159...". There does not seem to be any reason given for that section to be marked or any explanation of what that means. I might guess that the ".14159", simply because it is the first 5 decimal places $\pi$, is supposed to be the decimal part of $\pi$, $3- \pi$ but I have no idea what it is really intended to show

 

[ProfuselyQuarky]

but how the length .142 is exact??

0.14159 (and so on) is a definite number between 0 and 1. Just because there's a decimal, it doesn't mean that it's not "real" or that it's "infinite" like you've said along this thread.