A graph consisting of three coplanar curves, each graduated for a different variable so that a straight line cutting all three curves intersects the related values of each variable.

• 列线图解由三条共面曲线所组成的图，每一条曲线走向不同，因此截断这三条曲线的一条直线与每一条不同的曲线都以不同的变量相交