chore: use M_PI instead of PI parameter (#2747)

* changed PI variable value from 3.14 to M_PI

* changed PI variable to M_PI

* changed the degree_to_radians function

* comments removed

* docs: remove pi param

* fix: typo in function name

* changed degree to degrees

---------

Co-authored-by: [Divyansh Jain] <[jdivyansh51@gmail.com]>
Co-authored-by: realstealthninja <68815218+realstealthninja@users.noreply.github.com>

Author: 3 people

physics/ground_to_ground_projectile_motion.cpp

@@ -10,6 +10,7 @@
  */
 
 #include <cassert>   /// for assert()
+#define _USE_MATH_DEFINES
 #include <cmath>     /// for std::pow(), std::sin(), and std::cos()
 #include <iostream>  /// for IO operations
 
@@ -27,11 +28,12 @@ namespace ground_to_ground_projectile_motion {
 /**
  * @brief Convert radians to degrees
  * @param radian Angle in radians
- * @param PI The definition of the constant PI
  * @returns Angle in degrees
  */
-double degrees_to_radians(double radian, double PI = 3.14) {
-    return (radian * (PI / 180));
+
+double degrees_to_radians(double degrees){
+    double radians = degrees * (M_PI / 180);
+    return radians;
 }
 
 /**