I need help figuring out how to find these measurements.

We will have the following:
First, from properties of the parallelograms we will have that MR = RP; thus:
[tex]\begin{gathered} 2(5(a+8))=12a+52\Rightarrow10a+80=12a+52 \\ \\ \Rightarrow2a=28\Rightarrow a=14 \end{gathered}[/tex]Now, we will have that:
[tex]\begin{gathered} MR=110 \\ \\ RP=110 \\ \\ MP=220 \end{gathered}[/tex]