Question

Vector

Answer 1

how to do question 5b?

Answer 2

Well if you draw it out, that might help. Since a+b+c=0 you know that by a little algebra that:

a+b=-c

So c is really just the same length but in the opposite direction as the sum of the vectors a+b.

Answer 3

Draw the vectors on Cartesian coordinates with the vertex at the origin and vector "b" on the + x-axis. Then resolve vector "a" into its x and y components.