我们知道要求圆锥体的侧面积,必须知道圆锥顶点的角度,而小学生由于知识所限不会求圆锥体的角度,因而教材里就没有介绍求圆锥体侧面积的方法。那么是不是在小学知识范围内就不能求出圆锥的侧面积呢?不是的。如果我们将推导圆面积公式的转化方法迁移到求圆锥体的侧面积上来,就能把这一高中知识的问题,用 We know that the cone side of the area, we must know the angle of the cone vertex, and pupils due to knowledge of the cone will not ask the angle, so the teaching material is not introduced to find the method of cone side area. Is not it possible to find the side of the cone in the area of ​​elementary knowledge? If we move the method of deriving the conversion of the circular area formula to the area of ​​the side of the cone, we can use the problem of this high school knowledge