From Figure 1 drag a straight line l1 and l2, l1 and origin in parallel with pass, and l2, respectively, will be the slope of l1 and m1 are equal to the slope of l2 is equal to m2.
Figure 1 plots the l1 and l2 through the origin and parallel to l1 and l2, respectively, will be the slope of l1 is equal to m1 and the slope of l2 m2.
From Figure 1 straight line and L1 L2 through the origin, and parallel to the L1 L2 respectively. And will be a collection of L1 was M1 and slope. L2 was m2.