Chapter 1 - Introduction to Algebraic Expressions - Study Summary - Practice Exercises - Page 72: 2

$A=4\,ft^2$

Let the area of the rectangle be $A$. This gives, $A=l\cdot b$, where $l$ and $b$ are the length and width of the rectangle respectively. Substitute $l=8$ ft and $b=\dfrac{1}{2}$ ft, and then solve as follows: $A=(8\, ft)\cdot\left( \dfrac{1}{2}\, ft \right)=(8)\cdot\left( \dfrac{1}{2} \right)(ft\cdot ft)= \dfrac{8}{2}\, ft^2=4\,ft^2$