please answer of 6 of these but if you do then you get brainliest but answer all 6 and show the work on how to do it also for each problem

5. r×2×pi
7km×2×pi=43.98km
6. d×pi
20cm×pi=62.83cm
7. d×pi
8.5m×pi=26.70m
8. r×2×pi
11yd×2×pi=69.12yd
9. d×pi
6(2/5)ft×pi=20.11ft
10. r×2×pi
25in×2×pi= 157.08in