Integral of $$$\pi$$$

Apply the power rule $$$\int \pi^{n}\, d\pi = \frac{\pi^{n + 1}}{n + 1}$$$ $$$\left(n \neq -1 \right)$$$ with $$$n=1$$$:

$${\color{red}{\int{\pi d \pi}}}={\color{red}{\frac{\pi^{1 + 1}}{1 + 1}}}={\color{red}{\left(\frac{\pi^{2}}{2}\right)}}$$

Therefore,

$$\int{\pi d \pi} = \frac{\pi^{2}}{2}$$

Add the constant of integration:

$$\int{\pi d \pi} = \frac{\pi^{2}}{2}+C$$

$$$\int \pi\, d\pi = \frac{\pi^{2}}{2} + C$$$A