The operation in which two or more metal parts are joined together using high-intensity heat is welding.
Welding involves melting the base metals and adding filler material to create a strong joint when cooled.
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. 