To express $\sqrt{45}$ in its simplest radical form, we can start by factoring 45.

$45 = 9 \times 5$

Now, take the square root of 9 since it is a perfect square:

$\sqrt{45} = \sqrt{9 \times 5} = \sqrt{9} \times \sqrt{5} = 3\sqrt{5}$

Thus, the simplest radical form of $\sqrt{45}$ is:

$3\sqrt{5}$

Would you like more details on simplifying radicals, or do you have any questions?

Here are 5 related questions for further practice:

1. Simplify $\sqrt{75}$.
2. Simplify $\sqrt{50}$.
3. Simplify $\sqrt{18}$.
4. Simplify $\sqrt{80}$.
5. Simplify $\sqrt{72}$.

Tip: Always look for perfect squares when simplifying square roots to make the process easier!