周长计算器
求圆的周长和面积
公式
C = 2πr, A = πr²
Circumference = 2π times radius. Area = π times radius squared.
示例
r = 5
C ≈ 31.42, A ≈ 78.54
常见问题
关于 周长计算器
Calculate circumference and area of a circle from its radius.
求圆的周长和面积
Circumference = 2π times radius. Area = π times radius squared.
C ≈ 31.42, A ≈ 78.54
Calculate circumference and area of a circle from its radius.