Answer:
27 cm
Step-by-step explanation:
Hi there!
Let b be equal to the length of the base.
Form a proportion:
[tex]\displaystyle \frac{2}{3} =\frac{18}{b}[/tex]
Cross multiply:
[tex]3*18=2b\\54=2b\\b=27[/tex]
Therefore, the length of the base is 27 cm.
I hope this helps!