圆计算器(进阶) — 公式

Circle Calculations

Formulas

  • Area = pi × r²
  • Circumference = 2 × pi × r
  • Sector Area = pi × r² × (angle / 360)
  • Arc Length = 2 × pi × r × (angle / 360)

    • A sector is a "pie slice" of the circle defined by a central angle.

    计算示例

    A circle with radius 5, find area and a 90-degree sector.

    1. Area = pi × 25 ≈ 78.5398
    2. Circumference = 2 × pi × 5 ≈ 31.4159
    3. Sector area = 78.5398 × 90/360 ≈ 19.6350
    4. Arc length = 31.4159 × 90/360 ≈ 7.8540