So the area of a unit circle then is just Pi, keep that in mind because it'll come in handy later.

所以单位圆的面积就是 Pi，记住这一点，因为它以后会派上用场。

Now, Newton is particularly interested in N equals a half because the equation for a unit circle is X squared plus Y squared equals one.

现在，牛顿对 N 等于二分之一特别感兴趣，因为单位圆的方程是 X 平方加上 Y 平方等于 1。