Câu 1 :
uses crt;
var a, r, s : real;
begin
clrscr;
write('Nhap canh a = '); readln(a);
r := a / 4; s := (a * a) - ((r * r * 3.14) * 4);
write('Dien tich = ', s : 2 : 2);
readln
end.
Câu 2 :
uses crt;
var a, s : real;
begin
clrscr;
write('Nhap a = '); readln(a);
s := ((a / 2) * (a / 2) * 3.14) / 2 - ((a * (a /2)) / 2) ;
write('Dien tich = ', s * 4 : 2 : 2);
readln
end.
