The lateral surface area of a hemisphere is $693{\text{cm}}^2$. Its radius will be ________. (Take $\pi =\frac{22}{7}$)

The lateral (curved) surface area of a hemisphere is given by the formula:
$$\text{CSA}=2\pi r^2$$
Given that the lateral surface area is $693{\text{cm}}^2$:
$$2\times \frac{22}{7}\times r^2=693$$
$$\frac{44}{7}\times r^2=693$$
$$r^2=\frac{693\times 7}{44}$$
Dividing $693$ and $44$ by $11$:
$$r^2=\frac{63\times 7}{4}=\frac{441}{4}$$
Taking the square root on both sides:
$$r=\sqrt{\frac{441}{4}}=\frac{21}{2}=10.5\text{cm}$$
Thus, the radius of the hemisphere is $10.5\text{cm}$.