# Thread: Torus volume by using cylindrical shells

1. ## Torus volume by using cylindrical shells

Use cylindrical shells to find the volume of the torus obtained by revolving the circle $x^2+y^2=a^2$ about the line x=b, where b>a>0.

For this one, I can't figure out anything. I know what torus is, but I don't know how to solve this one.

Thank you.

2. Use the formula for the area of a circle.

$V=4{\pi}\int_{-a}^{a}(b-x)\sqrt{a^{2}-x^{2}}dx$

See why?.