Answer: P = 82 mm
Step-by-step explanation: Hello. The formula to find the perimeter is basically all the side lengths added together. So it would be 3.5(2) + 6(2), and that would get you 7cm + 12mm. However, this isn't complete, since you have to convert cm to mm. And 7cm in mm is 70mm. So 70mm + 12mm would get you 82mm.