12. Determine the length of the line segment

In the following figure, \(PQRS\) is a rhombus. Diagonals \(PR\) and \(QS\) intersect at \(O\). \(L\) and \(M\) are mid-points of \(OP\) and \(OQ\) respectively. If \(PR\) \(=\) 16 \(cm\) and \(QS\) \(=\) 30 \(cm\), then \(LM\) is:

 

 

The value of \(LM\) \(=\)  \(cm\)