Find the area of the quadrilateral \(PQRS\), in which \(PQ\) \(=\) 18 \(m\), \(QR\) \(=\) 21 \(m\), \(RS\) \(=\) 21 \(m\), \(SP\) \(=\) 20 \(m\) and \(QS\) \(=\) 22 \(m\). (Use \(\sqrt{2} = 1.41\), \(\sqrt{5} = 2.24\)).
Area of the quadrilateral \(PQRS\) \(=\) \(m^2\)
[Note: Round off your answer to two decimal places]