Raashi asked Ratul what challenges he had faced while volunteering.
Explanation: The question is converted into reported speech. The verb have faced in the direct speech changes to had faced in the past perfect tense to reflect the shift in time.
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.