1)

#include <iostream>

#include <math.h>

using namespace std;

int main ()

{

float a,b, P;

cout << "Please enter a, b :"<< endl;

cin>> a >> b;

P= (a+b)*2;

cout << P << endl;

return 0;

}

2)

#include <iostream>

#include <math.h>

using namespace std;

int main ()

{

float a, S;

cout << "Please enter a :"<< endl;

cin>> a ;

S= a*a;

cout << S << endl;

return 0;

}