Answer:
I'm assuming it's a rectangle because you only specified two sides. If so, the perimeter is 298 millimeters.
Step-by-step explanation:
Add the two numbers up, 29 + 120 = 149, and multiply it by 2. You get 298 millimeters.
Another way is to add 29 + 29 + 120 + 120 = 298 millimeters.