"A method that is easier to understand and does not make use of the sin function is based on the fact that if $X\\sim U(0,1)$ and $Y\\sim U(0,1)$, then $P[X^2+Y^2\\leq 1]=\\pi /4$ (see [\"Monte Carlo method on Wikipedia\"](https://en.wikipedia.org/wiki/Monte_Carlo_method)). The following code uses this approach:"
"It is then straightforward to obtain a (not really good) approximation to $\\pi$ by counting how many times, on average, $X^2+Y^2$ is smaller that 1:"