1, Helen formula in mathematics: given three sides of a triangle, a, b and c, then: (Helen formula) (p = (a+b+c)/2): s = sqrt [p (p-a) (p-b)] = sq.

2. Helen formula has also been translated into Helen formula. Legend has it that it was discovered by Xilun II, the ancient king of ancient Sula, and the triangle area was calculated by using the three sides of the triangle.