If the triangles are congruent means that angle O and R must be equal
[tex]\begin{gathered} 4x^2-4=3x^2+3x \\ 4x^2-3x^2-3x-4=0 \\ x^2-3x-4=0 \end{gathered}[/tex]factor
[tex]\begin{gathered} (x+1)(x-4)=0 \\ x=-1 \\ x=4 \end{gathered}[/tex]since we are talking about measurements the only solution must be a positive one
[tex]x=4[/tex]replace x
[tex]\begin{gathered} O=4\cdot(4)^2-6 \\ O=64-4 \\ O=60 \end{gathered}[/tex]