I do not understand were I went wrong.
1st is this line:
(it is saying that this (;) Error: excepted an expression)
2nd is this line:
cout<<"\nRadius is " << radius << set(8)<< "PI is" <<PI;
something is wrong with the second (<<)
// Program illustrating the use if #defines
#include <iostream>
using namespace std;
#define PI 3.14159265
#define radius
int main()
{
double circleArea;
// The area of a circle is PI * Radius * Radius
circleArea = PI * radius * radius;
cout<<"\nCircle Summary ";
cout<<"\nRadius is " << radius << set(8)<< "PI is" <<PI;
cout<<"\nThe circle's area is" << circleArea << "\n";
return 0;
}