物体平衡是力学的基础,而三力平衡是研究物体平衡的重点,也是高考命题的重点。当物体因受到三个力的作用而平衡时,这三个力可构成一个矢量三角形,灵活利用三角形的特点, The balance of objects is the basis of mechanics, and the balance of three forces is the focus of studying the balance of objects, and it is also the focus of the college entrance examination proposition. When an object is balanced by the force of three forces, these three forces can form a vector triangle, flexibly using the characteristics of the triangle,