semi circle
the radius is half of the diameter
another name for a half circle is semi-circle
It is a semi-circle
The Equator is the line that separates the earth into two hemispheres
Each meridian is a half-circle from the north pole to the south pole of the earth.
hemisphere
There is no specific name.
The circumference
depends on the information given, but radius is half of the diameter.
The perimeter of a circle is its circumference
A semicircle is half of a circle, formed by cutting a circle along its diameter line. It has the same curved edge as a circle but only covers half the area. The formula for the area of a semicircle is 1/2 times π times the radius squared.
Circumference.