depth 0.4[m] "Depth of the tower"
width 0.45[m] "Width of the tower"
height 1[m] "Height of the tower"
n 10 "Number of sections"
L height*(2*n-1) "Total height of the tower"
do1 3[cm] "Outer diameter tube 1"
di1 2[cm] "Inner diameter tube 1"
do2 2[cm] "Outer diameter tube 2"
di2 1.4[cm] "Inner diameter tube 2"
A1 pi/4*(do1^2-di1^2) "Area tube 1"
A2 pi/4*(do2^2-di2^2) "Area tube 2"