Uri 1012 solution | Area

/*Before seeing the code solution make sure that you have tried enough. Don’t copy- paste the whole code. Find out the logic. If you face any trouble, just inform me in comment.*/

#include<stdio.h>
main()
{
    double a,b,c,x,y,z,r,s,pi=3.14159;
    scanf("%lf%lf%lf",&a,&b,&c);
    x=0.5*a*c;
    y=pi*c*c;
    z=0.5*(a+b)*c;
    r=b*b;
    s=a*b;
    printf("TRIANGULO: %.3f\nCIRCULO: %.3f\nTRAPEZIO: %.3f\nQUADRADO: %.3f\nRETANGULO: %.3f\n",x,y,z,r,s);
    return 0;
}

//Happy_Coding