orthogonal group

例句：

1. 1. The orthogonal projection of a point on a plane is its distance from the origin.
   一个点在平面上的正交投影是它到原点的距离。
2. 2. The orthogonal relationship between two vectors is their dot product.
   两个向量之间的正交关系是它们的点积。
3. 3. The orthogonal group is a subgroup of the general linear group.
   正交群是一般线性群的一个子群。