Write a query identifying the type of each record in the TRIANGLES table using its three side lengths. Output one of the following statements for each record in the table:
- Equilateral: It’s a triangle with sides of equal length.
- Isosceles: It’s a triangle with sides of equal length.
- Scalene: It’s a triangle with sides of differing lengths.
- Not A Triangle: The given values of A, B, and C don’t form a triangle.
Input Format
The TRIANGLES table 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
Solution
- Conditions for a triangle with A, B, C sides will be A+B>C, A+C>B, B+C>A
- Conditions for equilateral triangle is when A=B and B=C
- Conditions for isosceles triangle is either A=B or B=C or A=C
- If not 2 and 3 then scalene
MySQL
SELECT IF(A+B>C AND A+C>B AND B+C>A,
IF(A=B AND B=C, 'Equilateral',
IF(A=B OR B=C OR A=C, 'Isosceles',
'Scalene')),
'Not A Triangle')
FROM TRIANGLES;
Oracle
SELECT
CASE
WHEN NOT ((a+b>c) AND (a+c>b) AND (b+c>a)) THEN 'Not A Triangle'
WHEN a = b AND b = c THEN 'Equilateral'
WHEN a = b OR b = c OR c = a THEN 'Isosceles'
ELSE 'Scalene'
END AS result
FROM triangles;
Source – Hackerrank