Lencho had all his doubts on people working in the post office. The irony of the situation is that Lencho blames those who had tried to help him out . In real life also we come across such situations. Many a time you would have tried helping someone and he may get a wrong message. Lencho thinks that the post office people have taken the money. But the fact is that they only tried to help him by sending money . But, on the other hand, Lencho thinks they have stolen his money. He even calls them crooks. Thus ,there is an element of irony in this situation.
In the adjoining figure, $\triangle CAB$ is a right triangle, right angled at A and $AD \perp BC$. Prove that $\triangle ADB \sim \triangle CDA$. Further, if $BC = 10$ cm and $CD = 2$ cm, find the length of AD. 
In the adjoining figure, TP and TQ are tangents drawn to a circle with centre O. If $\angle OPQ = 15^\circ$ and $\angle PTQ = \theta$, then find the value of $\sin 2\theta$. 