dimension of a projective variety

例句：

1. 1. The projective surface is a curved surface that projects into space.
   投影曲面是一个弯曲的表面，向空间延伸。
2. 2.The projective geometry of the plane is used to solve problems involving parallel lines and angles.
   平面的投影几何学用于解决涉及平行线和角度的问题。
3. 3.The projective transformation maps points in one plane to points on another plane.
   投影变换将一个平面上的点映射到另一个平面上的点。