192 
By addition we get 
V. + V, + V„=t*R* 
or the sum of the three projections is equal to the volume 
of the sphere. In this case the three component solids are 
three spheroids whose semi-axes are respectively It, Rcosa, 
Rcosa ; It, Itcos|3, Itcosj3 ; It, Rcos-y, Rcosy. 
