In the given figure, if \( ST \parallel QR \), \( QS = 3 \text{ cm} \), \( SR = 1.5 \text{ cm} \), and \( PT = 2.8 \text{ cm} \), then find the value of \( TR \). 
The product of $\sqrt{2}$ and $(2-\sqrt{2})$ will be:
If a tangent $PQ$ at a point $P$ of a circle of radius $5 \,\text{cm}$ meets a line through the centre $O$ at a point $Q$ so that $OQ = 12 \,\text{cm}$, then length of $PQ$ will be:
In the figure $DE \parallel BC$. If $AD = 3\,\text{cm}$, $DE = 4\,\text{cm}$ and $DB = 1.5\,\text{cm}$, then the measure of $BC$ will be: