What is the semicircle perimeter?

The perimeter of a semicircle consists of half the circumference of a full circle plus the diameter. The formula for the circumference of a full circle is (C = 2\pi r), where (r) is the radius. Therefore, the perimeter (P) of a semicircle can be expressed as (P = \pi r + 2r). This can also be simplified to (P = r(\pi + 2)).