Solution:
Given the quadrilateral;
The area, A of the quadrilateral is;
[tex]A=length\times width[/tex]
Where;
[tex]A=18km^2,length=3km,width=p[/tex]
Thus;
[tex]\begin{gathered} p=\frac{18km^2}{3km} \\ \\ p=6km \end{gathered}[/tex]
ANSWER: p = 6 kilometers
