SELECT 
    CASE 
        WHEN  A = B AND B = C AND A = C THEN 'Equilateral'
        WHEN A + B > C AND A = B OR B = C OR A = C THEN 'Isosceles'
        WHEN A + B > C AND A <> B AND B <> C AND A <> C THEN 'Scalene'
        ELSE 'Not A Triangle'
    END
FROM TRIANGLES;