Identifying Triangle

Write a query identifying the_type_of each record in theTRIANGLES table using its three side lengths. Output one of the following statements for each record in the table:

• Equilateral

  : It's a triangle with 3 sides of equal length.

• Isosceles

  : It's a triangle with 2 sides of equal length.

• Scalene

  : It's a triangle with 3 sides of differing lengths.

• Not A Triangle

  : The given values of A, B, and _C _don't form a triangle.

Input Format

TheTRIANGLEStable is described as follows:

Each row in the table denotes the lengths of each of a triangle's three sides.

Sample Input

Sample Output

Isosceles
Equilateral
Scalene
Not A Triangle

Explanation

Values in the tuple $(20, 20, 23)$ form an Isosceles triangle, because $A \equiv B$.

Values in the tuple $(20,20,20)$ form an Equilateral triangle, because $A \equiv B \equiv C$.

Values in the tuple $(20, 21, 22)$ form a Scalene triangle, because $A \not= B \not= C$.

Values in the tuple $(13,14,30)$ cannot form a triangle because the combined value of sides $A$ and $B$ is not larger than that of side $C$.

Thoughts:

1. Ideas from GeeksforGeeks

Code

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