curvature of a curve

例句：

1. 1. The shape of the planet is determined by its curvature.
   行星的形状由其曲率决定。
2. 2. The curved path of the river is a testament to its natural flow.
   河流曲折的路径是其自然流动的证据。
3. 3. The radius of curvature is the distance from the center of curvature to the point of maximum curvature.
   曲率半径是从曲率中心到最大曲率点的距离。