Given that

$$ radius=r=3\ in $$

$$ =>circumference\ of \ a \ circle=2\pi r=6\pi $$

$$ => Length\ of\ an\ arc=\frac{6\pi}{4} $$

$$ => Length\ of\ 4\ arcs=\frac{6\pi}{4}\times4=6\pi $$

$$ => Length\ of\ 4\ blue\ segments=6 \times 4 =24 $$

$$ \therefore Length=6\pi +24=6(3.14)+24=42.84\approx 43 $$