What is the formula for the perimeter of a triangle?

The formula for finding the perimeter of a triangle is derived from the need to measure the total distance around the triangle, which consists of the lengths of all three sides. In a triangle with side lengths denoted as (a), (b), and (c), the perimeter (P) is calculated by simply adding these three lengths together. Therefore, the correct formula is (P = a + b + c).

This approach is fundamental in geometry, as it applies to all types of triangles, regardless of their specific properties (such as being equilateral, isosceles, or scalene). The simplicity of this formula is one of its strengths, making it straightforward to apply when given the lengths of the triangle's sides. Understanding why the perimeter is calculated this way helps in visualizing the concept of distance around shapes, which is a key aspect of basic geometry.