Area / radius of truncated cone

So i have to put 6, 16, and 60 cylinders into my cone and then use them to get the elongation, I already have most of it I just can't figure out how to find the changing radius for each cylinder. for area adn radius I have:

for i=1:n

r(i) = r./n

A(i) = pi*(r(i))^2

I know radius is wrong but I cant seem to figure out what to put there, it also says wrong number of elements for the raius I am just lost.

Any help is appreciated!

Update: I change my radius to: (original radius is 2c) and changing radius of cone is ((R2-R2)/h)H (b=thickness=L./N

L(i) = (1/2)*(b(i))

r(i) = r(i) = ((2*c-c)/L)*L(i)

but now it says my radius equation either matrix dimensions need to agree, or when i put a '.' it says left and right different number of elements(still not sure if radius eq. is correct),