Question 979049
Larger semicircle area, {{{(1/2)pi*6.8^2}}}
Smaller semicircle area, {{{(1/2)pi*4.3^2}}}
The cross section area wanted,  {{{(pi/2)(6.8^2-4.3^2)}}}


The volume for the bench,  {{{pi(6.8^2-4.3^2)}}}  because the height is 2 feet.