#include <iostream>
#include <cmath>
using namespace std;
void meanings(double x1,double x2,double y1,double y2,double &angle,double &distance){
double dx=x2-x1;
double dy=y2-y1;
   distance=sqrt(dx*dx+dy*dy);
   angle=atan(dy/dx);
}
void elsemeanings(double length, double width, double &area, double &perimetr){
   area=length*width;
   perimetr=2*(length+width);
}

int main() {
    cout<<"---here---\n";
    double x1=0, y1=0, x2=3, y2=4;
    double dist, ang;
    meanings(x1,x2,y1,y2,ang,dist);
    cout<<"angle:"<<ang<<"\n";
    cout<<"distance;"<<dist<<"\n";
    
    double l=5,w=10;
    double a,p;
    elsemeanings(l,w,a,p);
    	
    	cout<<"area"<<a<<"\n";
    	cout<<"perimetr"<<p<<"\n";
	return 0;
}