tolong dijawab ya... itu dikumpulin besok..

1. K = 2πr = 2*(22/7)*3,5 = 22 cm

3. L = (1/4)π(D^2) = (1/4)*(22/7)*(42^2) = 1386 m^2

5. V = La*t = ((1/2)*6*8)*15 = 360 cm^3

6. V = La*t = (π.r^2)*t = ((22/7)*(10^2))*12 = 3769,91118 cm^3

9. r^2 = V : (π.t) = 1540:((22/7)*10) = 49
r = √49 = 7 cm