The perimeter of a square room is 216 \(m\). Find the area and the total cost of cementing the square room at a rate of \(₹\)9 per \(m²\).
Side of a square room \(=\) \(m\)
Area of a square room \(=\) \(m²\)
The total cost of cementing the square room \(=\) \(₹\).