1. Renewable Energy: Use of solar, wind, and hydroelectric power to reduce dependency on fossil fuels.
2. Water Conservation: Techniques like rainwater harvesting and efficient irrigation systems.
3. Waste Management: Recycling and composting to minimize landfill waste.
4. Green Building Design: Eco-friendly construction materials and energy-efficient designs.
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. 