SELECT 
    CASE 
        WHEN (A + B <= C) OR (A + C <= B) OR (B + C <= A) THEN 'Not A Triangle'
        WHEN A = B AND B = C THEN 'Equilateral'
        WHEN A = B OR B = C OR A = C THEN 'Isosceles'
        ELSE 'Scalene'
    END AS type_of_triangle
FROM TRIANGLES