If the radius of a sphere is $2.1\text{cm}$, then find the volume of the sphere.

The formula for the volume ($V$) of a sphere with radius $r$ is:
$$V=\frac{4}{3}\pi r^3$$

Given:

* Radius, $r=2.1\text{cm}$
* $\pi =\frac{22}{7}$

Substitute the values into the formula:

$$V=\frac{4}{3}\times \frac{22}{7}\times (2.1{)}^3$$

$$V=\frac{4}{3}\times \frac{22}{7}\times 2.1\times 2.1\times 2.1$$

$$V=4\times 22\times 0.1\times 2.1\times 2.1$$

$$V=88\times 0.441=38.808{\text{cm}}^3$$

Therefore, the volume of the sphere is $38.808{\text{cm}}^3$.