Write a pascal program to determine if a quadrangle is a square.

program zz1;

var a, b, c, d: integer; // set variables of integer type

begin

write (‘enter the first number’); // enter the first number from the keyboard

read (a);

write (‘enter the second number’); // enter the second number from the keyboard

read (b);

write (‘enter the third number’); // enter the third number from the keyboard

read (c);

write (‘enter the fourth number’); // enter the fourth number from the keyboard

read (d);

if (a = b) and (c = d) and (a = d) then writeln (‘the quadrilateral is a square’) // print the answer

else writeln (‘a quadrangle is not a square’);

end.