The formula for the volume of a cone is :
[tex]V=\frac{\pi r^2h}{3}[/tex]From the given problem :
the radius is 5cm and the height is 12
Substitute this values to the formula :
[tex]V=\frac{3.14(5)^2(12)}{3}=314\operatorname{cm}^3[/tex]The correct answer is Choice B.
Now for the tip
The volume of any solid is always :
V = Area of the base x Height
Note : If the solid or a 3D object is pointed, just divide it by 3
So the volume of this cone is :
Area of the base (Circle) = πr^2
height is h
And since it is pointed divide it by 3
That's the formula for the cone shown above became like that
Now for a cylinder
Area of the base (Circle) = the same area above
height is h
And it is NOT pointed so dont divide it by 3
The volume will be : V = πr^2h