Atul walks 5 km toward North and then turns to the right. After walking 3 km he turns to the right and walks 5 km. How far away is he from his starting position?

Let us trace Atul's path starting from point $O(0,0)$:
1. He walks $5\text{ km}$ North to reach point $A(0,5)$.
2. He turns right (East) and walks $3\text{ km}$ to reach point $B(3,5)$.
3. He turns right (South) and walks $5\text{ km}$ down to reach point $C(3,0)$.

The path forms a perfect rectangle $OABC$, where opposite sides are equal.
The distance between the final position $C$ and the starting position $O$ is equal to the length of side $AB$, which is $3\text{ km}$.