Answer:
The magnitude of your displacement is 4.52 Km
Step-by-step explanation:
Initially you walk 4.5 km in one direction. Then after turning to 45 degrees then you walk 6.4 km
So let us use cosine formula to find the distance
Distance =

Substituting the given values
Distance =

Distance =

Distance =

Distance =

Distance =

Distance = 4.52 km