Here is the solution based on the given problem above.
Given: Area of the piece of paper = 84 square inches
Width = 10 1/2 or 10.5 inches long
? = length of the piece of paper
To find the area of an object, the formula would be A= L x W
Now, let's substitute the given values above
84in2 = L(10.5in)
Now, divide both sides with 10.5 and we get 8.
L = 8 inches.
Therefore, the length of the paper is 8 inches.
Hope this solution helps.