I have four errora that I cant find nor can I fix so I kinda need help with this prog

[Guykanbar]

#include"stdafx.h"
#include <iomanip>
#include <iostream>
#include <math.h>
 
using std::cout;
using std::cin;
using std::endl;
using std::fixed;
 
int main()
{Pi = 3.1415926;
    double d;
    double degreeAngle;
    double D;
    double degreeAngle2;
    double Xm;
    double Ym;
    double Xt;
    double Yt;
    double g;
 
 
    cout<<"Enter Angle in degree"<<endl;
    cin>>degreeAngle;
 
    while(degreeAngle<=0 && degreeAngle>=90) cout<<"Enter a value between 0 and 90";
    else    cout<<"Enter value of d";
                cin>>d;
                while(d<=0) cout<<"Enter positive vale for d",
                else 
                {
                    D=tan((90- degreeAngle)*3.141592/180)
                        if(D>3500) cout<<"Target out of Range",
                        else 
                        {cout<<"Target is in Range";
                    cout<<"Enter value of Alfa 2 in degree";
                    cin>>degreeAngle2;
                    {if(degreeAngle2>90) degreeAngle2=degreeAngle2%90;
                    else if(degreeAngle2<=0) cout<<"Enter a positive value of Alfa 2";
 
                        cout<<"Enter your actual coordinates";
                        {
                            cin>>Xm;
                            cin>>Ym;
                            Xt=Xm+(D*cos(degreeAngle));
                            Yt=Ym+(D*sin(DegreeAngle));
                            cout<<"Your Target's current position is x="<<Xt<<"y="<<Yt<<endl
                                cout<<"Enter the value of g (the gravitation)";
                            cin>>g
 
                                degreeAlfa2=arcsin((g*D)/2*820*820)
 
                        };
};
 
};
                    };
}
 
                        return 0;
 

Here is my code. Here's what I have to do in this program. Im in a tank (AA88) I cant move from the tank nor can it move. I need to find my targets coordinates. I used Pythagore to find the distance from myself to the target. Then to find its coordinates I used Rayon (rayon=distance) Xt which is X of the target, Xt=Rcos (alfa) (alfa determined and inputed by user sooner) and for Yt=Rsin (alfa). Then I have to find the angle for firing, which I used to find a long physical properties about projectiles. My problem is that with this code I seem to have 4 errors that I dont ubderstand how to fix

[weaknessforcats]

This code:

Pi = 3.1415926;

needs a type for Pi. Probably this:

double Pi = 3.1415926;

The rest of your errors are in a deeply nested if-else where no attention was paid to the structure of an if-else.

The correct way to write these is:

if ( some test)
{
     //test is true
}
else
{
    // test is false
}

Unless you use the braces exactly as shown you will get odd results.

if ( some test)
 
     a = 5;       <- the semicolon terminates the if
 
else              <- this is now missing an if
{
    // test is false
}