tolong jawab ya,mksh yg udah jawab

[tex]2\pi \: r (r + t) \\ 2 \times \frac{22}{7} \times 7 \times (7 + 18) \\ \frac{308}{7} \times 25 \\ 44 \times 25 \\ 1100 \\ \\ v = 2\pi ^{2} t \\ \frac{22}{7} \times {9}^{2} \times 21 \\ \frac{22}{7} \times 81 \times 31 \\ \frac{37422}{7} \\ 5346[/tex]