Throw coins to find an approximation of pi.
Draw parallel lines of vertical and horizontal lines at equal intervals and throw coins randomly from above.
However , the distance between the parallel lines should be equal to the diameter of the coin.
The approximate value of pi can be obtained from the ratio of the number of coins thrown to the number of coins that overlap the grid points (the intersection of vertical and horizontal lines is called a grid point).
Let's explain the reason mathematically.