A class instance declared as a pointer

#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

struct TEllipse
{
    double Radius;
    double radius;
};

double GetTheRadius(const string s);
double Area(const double R, const double r);

int main()
{
    TEllipse Els;
    TEllipse* Elisp = &Els;

    cout << "Enter the dimensions of the ellipse\n";
    Elisp->Radius = GetTheRadius("Long Radius: ");
    Elisp->radius = GetTheRadius("Short Radius: ");

    cout << "\nCharacteristics of the ellipse";
    cout << setiosflags(ios::fixed) << setprecision(2);
    cout << "\nLong Radius:  " << Elisp->Radius;
    cout << "\nShort Radius: " << Elisp->radius;
    cout << "\nArea:         " << Area(Elisp->Radius, Elisp->radius);    
    
    return 0;
}

double GetTheRadius(const string s)
{
    double r;

    cout << s;
    cin >> r;
    return r;
}

double Area(const double R, const double r)
{
    const double PI = 3.14159;
    return R * r * PI;
}