Given, length of the room, I=21m breadth of the room, b=16m and the length of the longest rod that can be placed in the room =29m We know that, the length of the longest rod that can be placed in the room is the diagonal of the room (cuboid). We know, diagonal of a cuboid =√l2+b2+h2 ⇒29=√(21)2+(16)2+h2 ⇒(29)2=441+256+h2 ⇒841=697+h2⇒h2=144 ⇒h=12cm Hence, height of the room is 12cm.