A cute puppy walks 20 m at 30 degrees north of east and then continues another 45 m at 15 degrees south of east. Find the magnitude of the puppy's net displacement (or the distance from the starting point)

break each up into N, E components, then add.

20sin30N + 20cos30E -45sin15N+45cos15E=R

now combine the N, E vectors
xxxxN + yyyyE= R
magnitude of R=sqrt(xxxx^2 + yyyy^2)