Basic word problem that I am confused by

[LindseyL]

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

[theshadow]

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.

They give you n=27 so n goes from n=1 to n=27. Find the sq inches for the whole thing. This will be your last number a₂₇. They give you "48" for your first number a₁.

Plug n=1, n=27, a₁ and a₂₇ into the formula. Solve for the d. Then do the adding to get the number for n=2 to n=26.