[tex]\bf \textit{ratios relations for similar figures}
\\\\\\
\begin{array}{cccllll}
side&area&volume\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
\frac{s}{s}=\frac{s}{s}&\frac{s^2}{s^2}=\frac{area}{area}&\frac{s^3}{s^3}=\frac{volume}{volume}
\end{array}\\\\
-----------------------------\\\\
[/tex]
[tex]\bf thus
\\\\\\
\begin{array}{llll}
\cfrac{\textit{polygon A}}{\textit{polygon B}}\qquad &\cfrac{24^2}{15^2}=\cfrac{128}{x}
\end{array}[/tex]
solve for "x"