The sphere: Surface area and volume

The figure resulting from rotating a circle fixed by a diameter is called a sphere like the one we can see in the following picture:


The volume of a sphere has the following expression: $$$V=\dfrac{4}{3}\pi \cdot r^3$$$

To remember the expression of the area of the sphere, it is useful to remember that it is the derivative of the volume according to $$r$$ $$$A=4 \cdot \pi \cdot r^2$$$