circumference

circumference的音标是[ˌsɜːkjəm(ə)fɪə(r)]，基本翻译是周长。速记技巧是使用字母组合记忆法，可以与单词“circle”一起记，它们都有“圆”的意思。

circumference这个词的词源可以追溯到拉丁语词circums,意思是“环绕”，加上词根ferre,意为“携带”。因此，circumference意为“周长”或“圆周”。

它的变化形式主要有复数形式circumbirfurcations，表示“环绕的分支”或“分支的周长”。其他的变化形式还包括形容词circumferential和副词circumferentially。

相关单词有perimeter，这个词也表示周长，其词源和circumference类似，都是环绕的意思。此外，还有radius，表示半径，其词源可以追溯到拉丁语radius，意为“射线”或“杆”，与circumference的词源没有直接关系，但都与几何学有关。其他相关单词还有concentric，表示同心，其词源可以追溯到拉丁语con-和-centrica，意为“在同一圆心”或“在同一中心”，也与circumference有关。

总的来说，circumference这个词及其变化形式和相关单词都与几何学中的圆和圆周有关，描述了圆或圆弧的周长和半径等几何属性。

常用短语：

1. circumference of a circle

2. perimeter of a square

3. circumference of a cylinder

4. circumference of a cone

5. around the circumference

6. on the circumference

7. at the circumference

双语例句：

1. The circumference of the circle is equal to twice the radius times pi. (英语)

- 这个圆的周长等于半径乘以π的两倍。(汉语)

2. The perimeter of the square is equal to four times its side length. (英语)

- 正方形的周长等于边长的四倍。(汉语)

3. The circumference of the cylinder is equal to the radius times 2π. (英语)

- 圆柱体的周长等于半径乘以2π。(汉语)

4. The circumference of the cone is equal to the radius times 2π and multiplied by the height. (英语)

- 圆锥体的周长等于半径乘以2π再乘以高度。(汉语)

英文小作文：

The circumference of a circle is an interesting mathematical concept that we can measure by using a measuring tape or ruler. It is equal to twice the radius times pi, which is a constant that we can approximate with 3.14. The circumference of a square is also related to its side length, which is also a constant that we can measure using a ruler or tape measure. In addition, we can also measure the circumference of a cylinder and a cone using similar methods. These mathematical concepts are essential for understanding geometry and its applications in real life situations.