Just add the measurements of the side to get the perimeter. However, if you want the easy way, here are the formulas:
, where length of the rectangle shall be multiplied by 2, and same with the width of the rectangle
, where the S is the equal sides of it.
, where the subscript sides are the sides that finishes the triangle, and the base is the underline of the triangle.
, where the sides are the posts of the trapezoid, and the base is the top and under lines of it.
Parallelogram = same formula with Rectangle
Circle = technically, it's not perimeter, but it's CIRCUMFERENCE.
, where pi is 3.14, and d is the diameter of the circle, which passes thorough the center in a straight line completely.