Measuring tape is used to measure the distance covered during a long jump. It ensures accurate measurement from the take-off point to the landing point in the sandpit.
- Option (a): A stopwatch measures time, not distance.
- Option (b): A height chart measures height, not horizontal distance.
- Option (d): A weighing scale measures weight.
Thus, the correct equipment for measuring long jump is a measuring tape.
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. 