Question 431134
Subtract the outer circle from the inner circle
{{{ A = pi*(22/2)^2 - pi*(18/2)^2 }}}
{{{ A = pi*(484/4) - pi*(324/4) }}}
{{{ A = (pi/4)*(484 - 324) }}}
{{{ A = (pi/4)*160 }}}
{{{ A = 40*pi }}}
{{{ A = 125.664 }}} ft2