Functions

#include<iostream>
#include<vector>

double triangle_area1(double base, double height){
  double area;
  area = 1./2*base*height;
  return area;
}

int main(){
  double area;
  area = triangle_area1(2.,3.);
  std::cout << area << std::endl;
  
  return 0;
}

// Results: 3
void triangle_area2(double base, double height, double &area){
  area = 1./2*base*height;
}

void square_infor(double length, double &area, double &perimeter){
  area = length*length;
  perimeter = 4*length;
}

int main(){
  double area;
  double Area, Perimeter;
  triangle_area2(2.,5., area);
  std::cout << area << std::endl;
  square_infor(4.,Area, Perimeter);
  std::cout << Area << std::endl;
  return 0;
}
// Results: 
5
16
//