You know the side of each square is k. So that means the AREA of each square will be k

^{2}. Since there are ten squares total, that means the ENTIRE area will be 10k

^{2}. So a=10k

^{2}.

Now get the perimeter: just count the number of sides that are bolded. There are 16 sides to the figure, and since each side equals k, that's 16k. So p=16k.

Since the question says p=a, that means 16k=10k

^{2}. Divide both sides by k to cancel it out, and you get 16=10k. Then divide by 10 on both sides and you get 16/10=k, which reduces down to 8/5=k.