Fan light or transom.
another name for a half circle is semi-circle
still a window
It is a semi-circle
semi circle
The name for wood or stone that runs along the bottom of a window or door is the sill.The window sill got wet because I forgot to close the window when rain started.The stone door sill developed a long crack.
hemisphere
There is no specific name.
This is called a "transom". In the U.S., this name applies if the window is fixed or if it opens.
The archaic word for "window" is "embrasure." Technically, the word "embrasure" could be used for a window or the opening for a door.
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.
It is called a protractor.