cin输入，printf输出

#include<cstdio>
#include<iostream>
using namespace std;
int main()
{
    double a,b,c;
    cin>>a>>b>>c;
    printf("TRIANGULO: %.3lf\n",a*c/2);
    printf("CIRCULO: %.3lf\n",3.14159*c*c);
    printf("TRAPEZIO: %.3lf\n",(a+b)*c/2);
    printf("QUADRADO: %.3lf\n",b*b);
    printf("RETANGULO: %.3lf\n",a*b);
    return 0;
}