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docs/api/math/h/two-pi.md

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+# Math::TWO_PI
+
+```cpp
+constexpr float TWO_PI = 6.28318530717958647692f;
+```
+
+`TWO_PI` 是圆周率的两倍，即完整的圆周长对应的弧度值，约为 6.28318530717958647692。该常量常用于需要完整圆周旋转的场景，例如角度归一化、三角函数周期计算、圆形运动等。
+
+**示例：**
+
+```cpp
+#include <XCEngine/Math/Math.h>
+
+float fullCircleRadians = Math::TWO_PI;
+```
+
+## 相关文档
+
+- [Math 总览](h.md) - 返回 Math 概览