Write a program to find the area of an isosceles triangle.

program zz1;
var a, b, S: real; // set variables of non-integer type
begin
write (‘enter the side of an isosceles triangle’);
read (a);
write (‘enter the base of an isosceles triangle’);
read (b);
s: = b / 2 * sqrt ((a + b / 2) * (a – b / 2)); // find the area of an isosceles triangle using the formula
writeln (‘area of an isosceles triangle =’, s: 5: 2); // display the answer in the format of five characters for the whole number and two characters after the dot
end.