C + + Informatics Olympiad A one-pass question bank 1034 compute the Triangle area __c++

Calculate the area of a triangle


Time limit: 1000 ms Memory limit: 65536 KB
Number of submissions: 1813 Pass: 622


"topic description"
There is a triangle on the plane, its three vertex coordinates (x1, y1), (x2, y2), (x3, y3), then what is the area of the triangle, accurate to two decimal places.


Enter
Enter only one line, including 6 single-precision floating-point numbers, corresponding to x1, y1, x2, y2, X3, Y3, respectively.


Output
The output is also one line, the area of the output triangle, accurate to two digits after the decimal point.


"Input Sample"
0 0 4 0 0 3
"Output Sample"
6.00
Source


No
Source:
#include <iostream>
#include <iomanip>
#include <cmath>
using namespace Std;
int main ()
{
Double x1,x2,x3,y1,y2,y3,p,s,a,b,c;
Cout.precision (2);
cin>>x1>>y1>>x2>>y2>>x3>>y3;
A=sqrt ((x2-x1) * (x2-x1) + (y2-y1) * (y2-y1));
B=sqrt ((x3-x2) * (X3-X2) + (y3-y2) * (Y3-y2));
C=sqrt ((x3-x1) * (x3-x1) + (y3-y1) * (y3-y1));
p= (A+B+C)/2;
S=sqrt (p* (p-a) * (p-b) * (p-c));
cout<<fixed<<s;
return 0;
}