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.