1. Vitamin A is found in foods like carrots and papaya.
2. Protein is found in foods like peanuts and soybeans.
3. Calcium is found in foods like milk and green leafy vegetables.
4. Vitamin C is found in fruits like guava and lemon.
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.