declare an angle

[alexbg]

Hi, i have a trouble with a homework.The problem is that i dont know how to declare an angle in a triangle in cpp.
Pls help me.Its very important for me

[Disch]

int angle; ?

[alexbg]

yes, i did it.But after that i dont know how to tell to the program that its an angle between ,lets say, line s and line d?

[anilashanbhag]

essentially if ur angle is in radian measure

try defining a macro #define pi 3.14159

[alexbg]

excuse me, i am begginer, dont laugh at me, but where should i define it? i have done this so far :
#include "ccc_win.h"

using namespace std;
int angle;
int point;
int ccc_win_main()
{
Message dowhat(Point(-10,8.50),"Click three times to create a triangle ...");
cwin << dowhat;


Point p1 = cwin.get_mouse("");
Point p2 = cwin.get_mouse("");
Point p3 = cwin.get_mouse("");


cwin << Line(p1,p2) << Line(p1,p3)<< Line (p2,p3);

return 0;
}
the whole task is to enter a triangle and to calculate its minimal cos.I think if i define the angles the rest will be easy..