A physical activity facilitator maintains professional etiquettes by:
1. Effective Communication: Using polite and clear language when instructing participants.
2. Punctuality: Arriving on time and respecting schedules.
3. Proper Conduct: Demonstrating fairness, respect, and ethical behavior during activities.
4. Dress Code: Wearing appropriate attire to set a professional example.
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. 