1. The problem is to find the formula for the perimeter of a shape. 2. The perimeter is the total distance around the boundary of a two-dimensional shape. 3. For common shapes, the perimeter formulas are: - Square: $$P = 4s$$ where $s$ is the length of one side. - Rectangle: $$P = 2(l + w)$$ where $l$ is length and $w$ is width. - Triangle: $$P = a + b + c$$ where $a$, $b$, and $c$ are the lengths of the sides. - Circle (circumference): $$P = 2\pi r$$ where $r$ is the radius. 4. These formulas add up the lengths of all sides or the distance around the shape. 5. To use the formula, identify the shape and measure the necessary sides, then substitute into the formula and calculate. Example: For a rectangle with length 5 and width 3, perimeter is $$P = 2(5 + 3) = 2 \times 8 = 16$$. Final answer: The perimeter formula depends on the shape, but generally it is the sum of all side lengths.