Mathematical Reasoning

The triangle is not an equilateral or not an isosceles triangle or it is not an isosceles or it is not right angled

The triangle is not an equilateral triangle or not isosceles triangle and it is isosceles or it is not right angled

If the triangle is an equilateral triangle or an isosceles triangle then it is an isosceles triangle or not right angled

If the triangle is an equilateral triangle or an isosceles triangle then it is not isosceles triangle and it is not right angled