Program NhatNgu;
Uses crt;     //Khai bao thu vien
Const pi=3.14;      //Gan gia tri cua hang pi=3.14
Var r,cv,dt: real;     //Khai bao bien o dang so thuc
Begin
        Clrscr;
        Write('Nhap ban kinh: '); Readln(r);      //Nhap do dai ban kinh tu ban phim
        cv:=2*r*pi;     //Cong thuc tinh chu vi hinh tron
        dt:=r*r*pi;     //Cong thuc tinh dien tich hinh tron
        Writeln('Chu vi = ',cv:0:2);
        Write('Dien tich = ',dt:0:2);
        Readln
End.

Uses crt;
Var r, s, p: real;
Const pi=3.14;
Begin
Clrscr;
Write('Nhap ban kinh r = '); readln(r);
s:=pi*sqr(r);
p:=pi*2*r;
Writeln('Chu vi la: ',p:8:2);
Writeln('Dien tich la: ',s:8:2);
Readln
End.