




Introduction
Introduction
The method of washers involves slicing the figure into washer shaped slices and integrating over these. It is highlyappropriate for computing the volume of a torus.
Rotate the circle
By rotating the circle around the yaxis, we generate a solid of revolution called a torus whose volume can be calculated using the washer method.
Washer method
We revolve around the yaxis a thin horizontal strip of height dy and width R  r.
This generates a disk with a hole in it (a washer) whose volume is dV.
R = right hand "x" value of the circle =
r = right hand "x" value of the circle =
Volume of the torus
We get the volume of the torus by filling it with a very large number of very thin washers, that is by integrating dV from y = 1 to y = 1.