Câu 1:
Program bai_tap;
Uses crt;
Var a, Cv, S: real;
Begin 
Write ('Nhap canh a='); 
Readln (a);
Cv:= 4*a;
S:= a*a;
Writeln ('Chu vi hinh vuong la:', Cv:8:2);
Writeln ('Dien tich hinh vuong la:', S:8:2);
Readln
End.
Câu 2:
Program bai_tap;
Uses crt;
Var ncv, r : real;
Begin 
Writeln ('Nhap ban kinh r='); 
Readln (r);
ncv:= 2*r*3.14/2;
Writeln ('Nua chu vi cua hinh tron la:', ncv:8:2);
Readln
End.