Answer
252 ft²
Step-by-step explanation
1 yard is equivalent to 3 feet. Using this conversion factor, the equivalence of 7 yd is:
[tex]\begin{gathered} 7\text{ yd =}7\text{ yd}\cdot\frac{3\text{ ft}}{1\text{ yd}} \\ \text{ Simplifying the units:} \\ 7\text{ yd =}\frac{7\cdot3}{1}\text{ ft} \\ 7\text{ yd }=21\text{ ft} \end{gathered}[/tex]Similarly, the equivalence of 4 yards is:
[tex]\begin{gathered} 4\text{ yd }=4\text{ yd}{}\cdot\frac{3\text{ ft}}{1\text{ yd}} \\ 4\text{ yd }=4\cdot3\text{ ft} \\ 4\text{ yd}=12\text{ ft} \end{gathered}[/tex]Therefore, the length of the bed is 21 ft and the width is 12 ft.
Finally, the area of the bed (a rectangle) is calculated as follows:
[tex]\begin{gathered} A=legnth\cdot width \\ A=21\cdot12 \\ A=252\text{ ft}^2 \end{gathered}[/tex]