Lucy Ango'yuaq, from Baker Lake Nunvaut, is a prominent wall hanging artist. This wall hanging is called Geese and Ulus. It is 22 inches wide and 27 inches long and was completed in 27 days. Suppose on the first day she completed 48 square inches of the wall hanging, and in the subsequent days the sequence of cumulative areas comnpleted by the end of each day produces an arithmetic sequence. How much of the wall hanging did Lucy complete in each subsequent day? Express your answer in square inches.

So, I am completely lost.. I would assume you would use the equation tn=t1 + (n-1)d

But I am unsure of which numbers would fit where.. would the first 48 square inches be the t1 (first term?) or would it be the common difference? (d?)

Please Help!

-Lindsey