diff --git a/math/point_in_circle_keira780.cpp b/math/point_in_circle_keira780.cpp
new file mode 100644
index 0000000000..4f4698f106
--- /dev/null
+++ b/math/point_in_circle_keira780.cpp
@@ -0,0 +1,37 @@
+#include <iostream>
+#include <cmath>
+
+/**
+ * @brief 判断一个点 (x, y) 是否在以 (cx, cy) 为圆心、r 为半径的圆内
+ * @param x 点的横坐标
+ * @param y 点的纵坐标
+ * @param cx 圆心横坐标
+ * @param cy 圆心纵坐标
+ * @param r 圆的半径
+ * @return true 如果在圆内或圆上, false 如果在圆外
+ */
+bool isPointInCircle(double x, double y, double cx, double cy, double r) {
+    // 计算点到圆心的欧几里得距离的平方，避免开方运算提高效率
+    double distanceSquared = std::pow(x - cx, 2) + std::pow(y - cy, 2);
+    double radiusSquared = std::pow(r, 2);
+    
+    return distanceSquared <= radiusSquared;
+}
+
+int main() {
+    double cx, cy, r, x, y;
+    std::cout << "--- 圆形位置关系判定工具 ---" << std::endl;
+    std::cout << "请输入圆心坐标 (cx cy) 和半径 r: ";
+    if (!(std::cin >> cx >> cy >> r)) return 0;
+    
+    std::cout << "请输入待检测点的坐标 (x y): ";
+    if (!(std::cin >> x >> y)) return 0;
+
+    if (isPointInCircle(x, y, cx, cy, r)) {
+        std::cout << "结果：点 (" << x << ", " << y << ") 在圆内或圆周上。" << std::endl;
+    } else {
+        std::cout << "结果：点 (" << x << ", " << y << ") 在圆外。" << std::endl;
+    }
+
+    return 0;
+}