# Vector loop or not? (exploring addition)

A set of vectors form a

__loop__when you can place them head-to-tail and the head of the last vector touches the tail of the first vector. Here are some examples.## Examples of Loops

Here are some non-loops. Can you tell what is wrong? What makes them NOT vector loops?

## Non-Loops

Drag the vectors in sets 1, 2, 3, 4. Can any sets of vectors be made into loops? Which ones?

## Loop sets or not?

Drag the vectors around in sets V, W, U, Z. Try to make loops.

- Which sets
__cannot__make loops? - What vector can you add to the set so that you
__can__make a loop? - How does the new vector depend on the order you joined the original vectors head-to-tail?