# Revolutions of integrals - torus

The circle x=acost, y=asint, 0â‰¦tâ‰¦2pi is revolved about the line x=b, 0<a<b, thus generating a torus (doughnut). Find its surface area.

Area if the torus:_____________.

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A surface of revolution is formed by the rotation of a planar curve C about an axis in the plane of the curve and not cutting the curve. The Pappus--Guldinus theorem says that:

â€¢ The area ...

#### Solution Summary

The area of the torus is found by revolutions of integrals.

$2.19