Two reasons why prices of products vary between shops are:
1. Location of the shop – Shops in high-rent or high-demand areas may charge higher prices due to their operating costs.
2. Branding and quality – Different shops may sell products with varying quality or branding, which can result in price differences.
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.