在初二物理教学中,力臂的画法是个难点,尤其在弯曲较复杂的杠杆中,多数同学不能正确的画出力臂.为了解决此难点,我把几何知识“点到直线距离的画法”寓于力臂的画法之中,收到了良好的效果. In the physics teaching of the second day of the year, the painting method of the arm is a difficult point, especially in the more complex bending lever, most students cannot draw the arm correctly. In order to solve this difficulty, I point the geometry knowledge to the point of straight line distance. The law "into the arm of the painting method, received good results.