Hacker rank Type of Triangle

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