21. Determine the area of the region

\(ABCD\) is a square of side 7.8 \(cm\). \(P\), \(Q\), \(R\) and \(S\) are the mid-points of \(AB\), \(BC\), \(CD\) and \(AD\) respectively. When the four arcs drawn intersect at \(P\), \(Q\), \(R\) and \(S\), find the area of the unshaded region. [Use \(\pi\) \(=\) \(3.14\)]

 

 

The area of the unshaded region \(=\)102.7547.7668.3283.52  \(cm^2\)