d=200;//given, in mm
L=2000;//given,2m in mm
T=30*10^6;//given, in N.mm
Tmax=15*10^6;//given
Smax=200;//maximum allowable shear stress,given,in N/mm^2
angle=2*%pi/180;//maximum angle of twist,given,in degrees
G=25000;//given, in N/mm^2