Also, I just want to review that the Gaussian surface we chose has Gaussian  surface area vectors that are either parallel to or perpendicular to the electric field.

另外，我只想回顾一下，我们选择的高斯表面具有与电场平行或垂直的高斯表面积矢量。

If we had chosen a cube as our imaginary Gaussian surface, the angle between  the electric field and the area vector would have had all sorts of different values.

如果我们选择一个立方体作为我们的假想高斯表面，电场和面积矢量之间的角度将会有各种不同的值。

Because the Gaussian surface we chose was a sphere concentric with the point charge, the  electric field and the area vector were always in the same direction giving an angle of zero degrees  in the dot product.

因为我们选择的高斯表面是与点电荷同心的球体，所以电场和面积矢量始终朝同一方向， 从而在点积中产生零度角。