program b2;uses crt;var R:real;    cv,dt:real;const pi=3.14;Begin    clrscr;    write ('Nhap ban kinh R= ');readln(r);    dt:=pi*r*r;    cv:=2*pi*r;    writeln('Dien tich hinh tron la: ',dt:2:2);    writeln('Chu vi hinh tron la: ',cv:2:2);    readln;

program b3;uses crt;var b:longint;Begin        clrscr;        write('B = ');readln(b);        writeln('Binh phuong ',b,' = ',sqr(b));        writeln('Can bac hai ',b,' = ',sqrt(b):2:2);        write('Lap phuong ',b,' = ',sqr(b)*b);        readln

program b4;uses crt;var a:integer;Begin        clrscr;        write('nhap so (m): ');readln(a);        writeln(a,'m = ',a*100,'cm');        write(a,'m = ',a*10,'dm');        readln