Final answer:
The length of the missing side of the triangle is 0 units.
Step-by-step explanation:
To find the missing side of the triangle, we need to use the formula for the perimeter of a triangle, which is the sum of the lengths of all three sides. In this case, the perimeter is given as 8x-2. Since we don't know the length of the missing side, we can represent it as a variable, let's say 'a'. So, the equation becomes: a + a + 8x-2 = 8x-2. Simplifying this equation, we get: 2a = 0, which means that the missing side has a length of 0 units.