In computer graphics, objects such as spheres are usually approximated by simpler objects constructed from flat polygons (polyhedra). using lines of longitude and latitude, define a set of simple polygons that approximate a sphere centered at the origin. can you use only quadrilaterals or only triangles

Computer graphics is an art of drawing pictures on Computer Screen.

Computer graphics is made up number of pixels. Pixels is the smallest unit which can be represented on computer screen.

Basically there are two types of Computer graphics:

Interactive  Computer graphicsNon Interactive Computer graphics. Interactive Computer graphics: In Interactive Computer Graphics there is a two way communication between computer and user. Here the user is given some control over the image. Non Interactive Computer graphics: is also known as passive computer graphics here in which user does not have any kind of control over the image.