In a triangle with side lengths 5, 10 and x, what is the sum of all possible integral values of x?
The triangle inequality states that the sum of the 2 smallest sides must be greater than the largest side.
This means that x can be anywhere from 6 to 14, because \(6 + 5 > 10\) and \(5+10>14\).
Now, we need to find the sum of all the numbers between 6 and 14.
Can you take it from here?