area curve

例句：

1. 1.The area curve of the earth's surface is used to calculate the distance between two points on the earth's surface.
   地球表面区域的曲线用于计算地球表面两点之间的距离。
2. 2. The area curve of a river can be used to estimate the width of the river at different depths.
   河流的面积曲线可以用来估计不同深度处的河流宽度。
3. 3.The area curve of a mountain range can help us understand the shape and size of the mountain range.
   山脉的面积曲线可以帮助我们了解山脉的形状和大小。