Energy-giving foods primarily provide carbohydrates and fats, which are essential for supplying energy to the body. Vitamins and minerals are essential for other bodily functions but are not the primary energy sources.
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.