Question

The internal dimensions of a rectangular box are $12cm\times xcm\times 9cm$. If the length of the longest rod that can be placed in this box is 17 cm; find x.

• A. 6 cm
• B. 8 cm
• C. 4 cm
• D. 2 cm

Answer 1

Answer: (B)

8 cm

Diagonal(d)$=\sqrt{l^2+b^2+h^2}$

$d^2={17}^2={12}^2+x^2+9^2$
$289=225+x^2$
$x=8cm$