Two activities of motor development in a 3 to 6-year-old child are:
1. Running and jumping – At this age, children develop their gross motor skills, enabling them to run and jump with more coordination and speed.
2. Drawing and building – Fine motor skills improve, allowing children to hold a pencil to draw and stack blocks to build structures.
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.