Adapted from an image in Back to Back activities, 2 vectors are defined as a and b and the activity asks how many further vectors can be defined in terms of a and b. The image gives all of the other lines defined as vectors in terms of a and b.

Looks like a great activity... Im not sure why vector KD is 2b??? I would also include statements about B, F, H, J, E, K, N being midpoints. Otherwise, there are quite a lot of geometric assumptions the students will need to make - which is what we don't want them to do.