Calculate the approximate value of π
The approximate value of π can be calculated by the formula 1=5*π= 15.7, where 1 represents the side length of the square and 15.7 represents the perimeter of the square.
Cones and cylinders with the same bottom and height
A cone with the same base and height is 1/3 cylinders. This trick can help us better understand and remember the relationship between a cone and a cylinder.
Calculate cone volume
The trick to calculate the volume of a cone is to first calculate the volume of a cylinder with the same base height, and then divide it by the area of the base. For example, when the height of the cone is 3 and the radius of the bottom surface is 10, the volume of the cylinder with the same height as the bottom surface of the cone is 10π, and the area of the bottom surface is 10π, then the volume of the cone is 10π/3 = 15.