The usual poster is in the shape of a rectangle. The formula for the area of a rectangle is written below:
A = LW
where L and W are the length and width dimensions
From the relationship described,
A = 2.5 ft²
W = 11/4 ft
Substituting this to the area equation:
2.5 ft² = L(11/4 ft)
Solving for L,
L = 10/11 ft