A semicircle is a two-dimensional geometric object consisting of an arc and a segment that together enclose an area in the shape of half a circle.
The radius of a semicircle is defined as the distance from the midpoint of the segment to any point of the arc.
The perimeter and the area of a semicircle with the radius r can be calculated using the following formulas. PerimeterAreaP=πr+2rA=21πr2