Playing around with making calculators and running into a problem with PI

[pmiccich]

Im making a volume calculator and im running into a problem, for some reason no matter what i do the final answer is always "3141.59" so basiclly PI with the decimal point moved over. The code is very long since it contains several other calculators, so ill just show the area of the code that matters to this problem.

  


else if (V_choice == "3"){
            
double V_pi = M_PI;
        double V_length = 0.0;
        double V_width = 0.0;
        double V_height = 0.0;
        double V_radius = 0.0;
        double V_final = 0.0;
        double V_pow = 0.0;
        double V_final1 = 0.0;
        string V_choice = "";

            cout <<"Pleas enter the radius: "<<endl;
            cin >> V_radius;
            
            V_pow = pow (V_radius , 3);
            
            V_final1 = (V_pi * V_pow);
            
            cout <<"The volume of the sphere is " << V_final1 <<endl;
            
        }

[pmiccich]

I must point out there are allot of un-used values in there because like i said there are several other calculators with this one.

[pmiccich]

and something im realizing now but a (4/3) belongs before the V_pi, i think i had it in but took it out to play around with.

[Mats]

It's just a case of having your formula incorrect. It should be:

V_final1 = (4.0d/3.0d) * pi * pow(V_radius,3);

(4/3 pi r ^ 3)

[pmiccich]

thank you very much!... haha, I feel kinda stupid.