we have that
the distance around the inside of the track is equal to two times the length of the rectangle plus the circumference of one circle (two half circles is the same that one circle)
therefore
[tex]P=2\cdot(84.39)+2\cdot\pi\cdot r[/tex]the radius of the circle is
r=73/2=36.5 m -----> the radius is half the diameter
substitute
[tex]\begin{gathered} P=2\cdot(84.39)+2\cdot\pi\cdot36.5 \\ P=(168.78+73\pi)\text{ m} \end{gathered}[/tex]the answer is