Overall: 3.14 * 6 * 6 * 9 =1017.36 (cm3)
Cm hole: 3.14 *1*1* 9 *12 = 339.12 (cm3).
10 17.36-339. 12 = 678.24 ~ ~ 678(cm3)
p30.5
2 cm = 0.02 m
1/3*28.26*2.5 divided by (10 * 0.02) =117.75 (m3).
p30.6
3. 14*2*2*4=50.24(dm3)
I want to open a model training class. What formalities and certificates are needed?
The establishment of schools and oth