Given that

$$radius=r=3in$$

$$=>circumferenceofacircle=2\pi r=6\pi$$

$$=>Lengthofanarc=\frac{6\pi }{4}$$

$$=>Lengthof4arcs=\frac{6\pi }{4}\times 4=6\pi$$

$$=>Lengthof4bluesegments=6\times 4=24$$

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