select 
case
    when (A+B) <= C or (B+C) <= A or (A+B) <= B then 'Not A Triangle'
    when A = B and B = C and C = A then 'Equilateral'
    when A = B or B = C or C = A then 'Isosceles'
    else 'Scalene'
end as Output
from TRIANGLES;