Question

let \[P_n\] be the perimeter of n-sided gon inscribed in the circle with radius r
a) show that \[\lim_{n\to \infty}P_n=2nr\sin(\frac{\pi}{n})\]

Answer 1

any ideas here.
what i thought of is see the perimeter in term of sides "s"
so the perimeter is \[P_n=ns\]
I'm looking for how to write s in otherway

Answer 2

i am going to use the case n=8 to develop a general formula

Answer 3

oh i see, well i started do some similar things
let me see where you take it

Answer 4

that limit has some problem, n should not present on right hand side