| 摘要 |
A device that teaches the relationship between a cylinder's surface areas and volume, its diameter and radius, the top circle circumference and area, the arc length, the sector area, the volume of a slice, the front area of the slice and the side area of the slice. The device includes a transparent hollow outer half-cylinder (1), and a solid inner half-cylinder (2) that can rotate around a common center (3) for both the inner and outer half cylinders. The outer half-cylinder has marked off units around the 180 degrees of the half-cylinder. The equations of arc length and sector area along with examples of their meanings are shown on the top half circle. The inner half-cylinder also has marked off units around the 180 degrees of the half-cylinder. The equations for volume of a slice, the front area of the slice, and the side surface area of the slice are shown. |
