Math help 10 points best answer?

Okay, the perimeter is all the side lengths combined. Like in a crime scene, that usually have the perimeter taped of the location of where it happened. Well, so if they ask for the perimeter of a triangle, basically you add all the sides, just like you do with squares and rectangles. So for all these questions, count how many sides the shape has and then you multiply it by the side length, and whala! there's your answer (: