program tin8;

uses crt;

var a:integer;

const pi=3,14;

begin

clrscr;

writeln('moi nhap ban kinh a');readln(a);

writeln(' dien tich hinh tron la ',a*a*pi:4:0);

writeln('chu vi hinh tron la ', 2*a*pi:4:0);

readln

end.

7.

var a,b:integer;

begin

write('Nhap chieu dai: ');readln(a);

write('Nhap chieu rong: ');readln(b);

writeln('Chu vi la: ',(a+b)*2);

write('Dien tich la: ',a*b);

readln;

end.

8.

const pi=3,14;

var a: integer;

begin

write('Nhap ban kinh: '); readln(a);

writeln('Dien tich hinh tron la: ',pi*a*a:0:2);

write('Chu vi hinh tron la: ',2*a*pi:0:2);

readln;

end.