tolong bantu jawab yh! soalnya, besok di kumpul

No. 1
Luas permukaan kubus = 6r^2 = 6 x 15^2 = 6 x 225 = 1.350 cm^2

No. 2
Luas permukaan kubus = 6r^2
249 = 6r^2
r^2 = 41,5
r = 6,44 cm

Volume = r^3 = (6,44)^3 = 267,34 cm^3

No. 3
Keliling alas = 4r
36 = 4r
r = 9 cm

Volume kubus = r^3 = 9^3 = 729 cm^3

No. 4
V kubus = r^3
1.000 = r^3
r = 10 cm

Luas permukaan kubus = 6r^2 = 6 x 100 = 600 cm^2

No.5 
Luas permukaan kubus = 6r^2
150 = 6r^2
r^2 = 25
r = 5 cm

Volume kubus = r^3 = 5^3 = 125 cm^3