Mark Brainliest please
Answer:x+1
The perimeter of a certain polygon is the sum of the measures of all its sides. If we are to use this concept with the given polygon above then that would be,
P = (3x + 1) + x + x + ?
We are also given that the perimeter is equal to 6x + 2. We substitute this to the equation derived,
6x + 2 = (3x + 1) + x + x + ? Simplifying, 6x + 2 = 5x + 1 +? ? = x + 1 Answer : the last side or ? is equal to x + 1.
