# What is the diagonal of a rectangular room which measures 18 feet by 21 feet?

$d \cong 27.6586 f e e t$
${d}^{2} = {18}^{2} + {21}^{2}$
${d}^{2} = 324 + 441$
$d = \sqrt{765} \cong 27.6586 f e e t$