Find the base area of a cone with a radius of 5cm.

Concept: We know the base area of a cone $=\pi r^2$.

Here, $r=5\text{cm}$.

Now, base area of a cone $=\pi r^2$

$\Rightarrow \pi \times 5^2$

$\Rightarrow 25\pi$

Hence, the base area of given cone is $25\pi {\text{cm}}^2$.