How Do You Calculate Total Displacement Using the Component Method?

[heythere1010]

Homework Statement

Use the componant method to determine the total displacement given by the two vectors shown in each diagram.

Homework Equations

The Attempt at a Solution

I thought I just had to find the third unknown side, and use the pythagorean theorem, but I was getting the wrong answer. My book says 11 km.

Any help is appreciated.

 

[PhanthomJay]

You've got to add up the x components , add up the y components, then use Pythagoras