有些几何题,教师如果引导学生用一个已知量或可求得的量代替另一个相等的量的方法思考,就可使问题迎刃而解。例1 一个圆锥的高和底面半径都等于一个正方体的棱长,已知这个正方体的体积是150立方厘米,求圆锥的体积。解:设正方形的棱长为a厘米,则圆锥的高和底面半径都为a厘米。 Some geometric questions, teachers can lead to the problem of solving the problem if they guide students to use a known amount or amount available to replace another equal amount. Example 1 The height of a cone and the radius of the base are equal to the length of a cube. The volume of this cube is known to be 150 cubic centimeters, and the volume of the cone is obtained. Solution: Let the square edge length of a centimeter, then the cone height and bottom radius are a centimeter.