Parenthesis NOT ALLOWED in SQL CASE

My MySQL journey!

Today I was trying to solve the valid triangle problem (GeekForGeeks article link) using MySQL 8.0 (in LeetCode). I was trying to use CASE statement and kept on getting error! My query was:

select x, y, z, 
        case
            (when x + y > z and 
            y + z > x and 
            x + z > y then 'Yes' 
                else 'No' end) as triangle
from Triangle

After a lot of searching through StackOverflow and MySQL documentations I found out what was wrong - I had an extra pair of parenthesis!!!

Correct query:

select x, y, z, 
        case
            when x + y > z and 
            y + z > x and 
            x + z > y then 'Yes' 
                else 'No' end as triangle
from Triangle 

Note: No parenthesis after CASE.