Respuesta :

28-21=7

thickness = 2x7=14

[tex]volume = \frac{1}{4} \pi \times h( {ro}^{2} - {ri}^{2} ) \\ = \frac{1}{4} \times 3.14 \times 14( {35}^{2} - {21}^{2} ) = 8620.276[/tex]