Answer
14.4 ft
Work Step by Step
Write a proportion. Height is to height as length is to length.
$\frac{30}{24}=\frac{18}{x}$ $\longrightarrow$cross multiply to solve for x
$30x=24\times18$ $\longrightarrow$multiply
$30x=432$ $\longrightarrow$multiplication property of equality
$30x\div30=432\div30$ $\longrightarrow$divide
$x=14.4$