4. (3 points) Three sectors with a radius of 100 cm and a central angle of $60^{\circ}$ are placed as shown in the figure; then, the perimeter of this enclosed figure is $\qquad$ cm. ( $\pi$ is taken as 3.14)
【Answer】Solution: According to the analysis, the closed figure is composed of three arcs,
and the arc lengths of the three sectors are equivalent to the arc length of a sector with a radius of 100 cm and a central angle of $180^{\circ}$, the perimeter of the closed figure $=2 \times \pi \times 100 \times \frac{1}{2}=100 \times 3.14=314$ cm.

Therefore, the answer is: 314