Check the picture below.
so we really have the perimeter of a 10x10 rectangle and a circle with a radius of 5.
[tex]\stackrel{\textit{\Large total perimeter}}{\stackrel{\textit{rectangle}}{(10+10+10+10)}+\stackrel{\textit{circle}}{(2\cdot \pi\cdot 5)}}\implies 40+10\pi \stackrel{\textit{rounded up}}{71.42}[/tex]
