1.  $r = \frac{200}{2} = 100$ 2.  $C = 2\pi r = 2\pi \times 100 = 200\pi \approx 628.3$ 3.  $C = \pi r = \pi \times 100 = 100\pi \approx 314.2$ 4.  $C = \pi r + 2r = 100\pi + 200 \approx 314.2 + 200 = 514.2$ 5.  $\frac{514.2}{314.2} \approx 1.64$