semuanaya apa jawabannya dari no12 sampai no 15

12. K = 2 × 22/7 × 7
= 44 cm (C)
13. L = 22/7 × r^2
1.386 = 22/7 × r^2
1.386 × 7 = 22 × r^2
9702 ÷ 22 = r^2
441 = r^2
r = √441 = 21 cm (D)
14. 3.850 × 7 = 22 × r^2
26950 ÷ 22 = r^2
1225 = r^2
r = √1225 = 35 cm (A)
15. K = 1/4 × 2 × 22/7 × 28
= 1/4 × 44 × 4
= 44 cm (A)