Copyright © University of Cambridge. All rights reserved.

## 'Corridors' printed from http://nrich.maths.org/

9 identical squares of side 2 units are separated by empty
strips also of 2 units width.

What is the shortest route from A to B, assuming you can only go
around the edges of the squares?

Now, consider 27 identical cubes of side 2 units which are
separated by corridors also of 2 units width. What is the shortest
distance from A to B?