Find the area of a triangular park, two of which sides are 5 \(m\) and 8 \(m\), and the perimeter is 20 \(m\). Also, find the cost of levelling the field at a rate of \(₹\)15 per square metre? (Use \(\sqrt{3} = 1.73\))
Area of the triangular park \(=\) \(m^2\)
Cost of levelling the park \(=\) \(₹\)
[Note: Round off the area up to two decimal places and round off the cost to the whole number.]