31. Among triangles with area 35 square units that have a side of length 15 units in common, what is the minimum perimeter?
[(1)] $30$
[(2)] $32$
[(3)] $34$
[(4)] $36$
\textbf{31.} Among triangles with area 35 square units that have a side of length 15 units in common, what is the minimum perimeter?
\begin{itemize}
\item[(1)] $30$
\item[(2)] $32$
\item[(3)] $34$
\item[(4)] $36$
\end{itemize}