A particle undergoes three displacements.

Question

The first has a magnitude of 15 m and makes
an angle of 40 ◦ with the positive x axis. The
second has a magnitude of 6.2 m and makes
an angle of 158 ◦ with the positive x axis. After the third displacement the particle returns to its initial position.

Find the Magnitude of the third displacement.
Answer in units of m.

Answer 1

Edit: Part 2
Find the angle of the third displacement.