🔄 终边相同的角计算器Coterminal Angle Calculator
求与给定角终边相同的角（θ ± 360°·k），给出 0°–360° 与 −180°–180° 内的标准角、所在象限和参考角，支持角度、弧度和 π 的倍数，也可判断两个角是否终边相同。Find angles coterminal with a given angle (θ ± 360°·k): its standard position in 0°–360° and −180°–180°, quadrant and reference angle, in degrees, radians or multiples of π — and check whether two angles are coterminal.
使用说明与常见问题How-to & FAQ
「终边相同的角计算器」是什么？What is the Coterminal Angle Calculator tool?
求与给定角终边相同的角（θ ± 360°·k），给出 0°–360° 与 −180°–180° 内的标准角、所在象限和参考角，支持角度、弧度和 π 的倍数，也可判断两个角是否终边相同。Find angles coterminal with a given angle (θ ± 360°·k): its standard position in 0°–360° and −180°–180°, quadrant and reference angle, in degrees, radians or multiples of π — and check whether two angles are coterminal.
如何使用「终边相同的角计算器」？How do I use the Coterminal Angle Calculator tool?
在「终边相同的角计算器」中，填写「角」、「单位」、「列出几组（正负各几个）」、「第二个角（可选，判断是否终边相同）」等参数，结果会随输入实时计算并显示在下方。In the Coterminal Angle Calculator: Fill in "Angle", "Unit", "How many to list (each direction)", "Second angle (optional, coterminal check)"; results are recalculated instantly as you type.
什么是终边相同的角？What are coterminal angles?
从 x 轴正方向出发、终边落在同一位置的角，彼此相差 360° 的整数倍（弧度为 2π 的整数倍），即 θ + 360°·k。Angles in standard position that end on the same ray; they differ by whole multiples of 360° (2π radians): θ + 360°·k.
参考角怎么求？How is the reference angle found?
参考角是终边与 x 轴所夹的锐角（或 0°、90°）：第一象限为 θ，第二象限 180° − θ，第三象限 θ − 180°，第四象限 360° − θ（θ 先化到 0°–360°）。It is the acute angle (or 0° or 90°) between the terminal side and the x-axis: θ in Quadrant I, 180° − θ in II, θ − 180° in III and 360° − θ in IV, with θ first brought into 0°–360°.
计算精度如何？How precise are the results?
「终边相同的角计算器」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Coterminal Angle Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「终边相同的角计算器」免费吗？需要注册吗？Is the Coterminal Angle Calculator free? Do I need an account?
「终边相同的角计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Coterminal Angle Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.