Surface Area and Volume

Here is a question from 7.3 in the text book :










r=d/2 v=πr² x h
r=8/2 v=(3.14x4x4) x 10m
r=4m v=50.24m² x 10m
v= 502.4m³
Now, since it is only half of a cylinder, I have to divide by 2
502.4m³/ 2= 251.2m³

The area of the semi-circular trough is 251.2cm³

Here is a question from 7.4 in the textbook :


____
³ )8000 = 20 d/2=r v= πr² x h
20/2=r v= (3.14x10x10) x 20
10cm=r v= 314cm²x 20cm
v= 6280cm³
The volume of the vase is 6280cm³