Hitunglah luas dan keliling bangun yang diarsir

Luas :
[tex]( \frac{45}{360} \times 3.14 \times {11}^{2} ) - ( \frac{45}{360} \times 3.14 \times {6}^{2} ) \\ = ( \frac{1}{8} \times 3.14 \times {11}^{2} ) - ( \frac{1}{8} \times 3.14 \times {6}^{2} ) \\ = 47.4925 - 14.13 \\ = 33.3625 {cm}^{2} [/tex]
keliling :
[tex]( \frac{1}{8} \times 3.14 \times 2 \times 11 + 2 \times 11) - ( \frac{1}{8} \times 3.14 \times 2 \times 6 + 2 \times 6) \\ = 30.635 - 16.71 \\ = 13.925cm[/tex]