Think about how many edges the shape in the middle has.
Rather than counting them all you might find that you can think of them as being in groups - how many groups?
How many edges to each group?
So many edges altogether?
How long is each edge?
So the perimeter (the distance around the shape in the middle) is ????
Although just counting them wouldn't actually take that long
Are these questions being set by someone else? If they are in a book you have bought, is there a version with the answers in the back?