The longest rod that can be placed inside the room will be equal to the length of the roomâs diagonal. \(\therefore\) The length of the rod will be \(\sqrt{a^2 + b^2 + c^2}\) units Now, \(a^2 + b^2 + c^2 = (a + b + c)^2 - 2(ab + bc + ca)\) \(= 25^2 - 2 \times 240.5\) \(= 625 - 481\) \(= 144\) \(\therefore\) The length of the rod will be \(\sqrt{144}\) units = 12 units (Answer)