Another name for half a circle is a semicircle.
It is a semi-circle
There is no specific name.
It is called a protractor.
Each meridian is a half-circle from the north pole to the south pole of the earth.
Half a circle is called a SEMI-CIRCLE
Half a circle is called a semi-circle. Sometimes it is called a half-moon.
a half circle? a half? semi circle? half sphere?