Question

Need help with 5 physics questions !!!!!

1. How can you measure the distance an object has moved?
2. How can you measure the magnitude of the displacement of an object?
3. How can you calculate the displacement of an object?
4.How did the calculated lenght of the displacement vector compare with the measured lenght of the displacement vector?
5. Describe the condition in which it would be impossible to actually measure a displacement?