角度换算
度、弧度、梯度转换
常用角度：
- 直角 = 90° = π/2 rad ≈ 1.5708 rad
- 平角 = 180° = π rad ≈ 3.1416 rad
- 周角 = 360° = 2π rad ≈ 6.2832 rad
- 1 rad ≈ 57.2958°
- 直角 = 90° = π/2 rad ≈ 1.5708 rad
- 平角 = 180° = π rad ≈ 3.1416 rad
- 周角 = 360° = 2π rad ≈ 6.2832 rad
- 1 rad ≈ 57.2958°