Use the Triangle Inequality Theorem (see picture above) to solve this problem.
Two sides of a triangle measure 11 and 3. Identify the side measure that would NOT create a triangle.
According to the Triangle Inequality Theorem, in a triangle the sum of the lengths of any two sides must be greater than the length of the third side.
In this case, two sides measure 11 and 3. The third side would have to be less than the sum of these two sides (11 + 3 = 14) but greater than the difference of these two sides (11 - 3 = 8).
So, any side length that is less than 8 or greater than 14 would not create a triangle.
Therefore, a side measure of 15 would NOT create a triangle with sides of 11 and 3.