Question 1041066
Is the thickness of the wall of the cylinder 4"? And are you looking for the radius including the wall thickness of the tube?
:
r^2Pi(h)= 810
r^2Pi = 810/10
r^2 = 81/Pi
r = sqrt25.78 = 5.1 is the internal radius
:
If EACH wall is 4": 5.1+4 = 9.1 is the outside radius
IF BOTH walls, together, are 4": 5.1+2 = 7.1 is the outside radius
:
See picture below:
*[illustration radius.JPG]