A semi-circle.
2d
A television set is a 3D shape. The image (picture) on the television screen is a 2D shape. 3D is when it has length, width, and height. 2D is only length and width.
Yes a triangle is a 2D polygon shape
As a 2D polygon shape it is an 8 sided octagon.
A hemisphere is a three dimensional shape that is essentially the same as half of a sphere.
A semi-circle.
A hemisphere is a 3-d shape and so does not have a name as a 2-d shape. 2-d sections of a hemisphere can be circles, semicircles, or sections of circles, depending on the inclination of the intersecting plane.
It's a 2D shape.
A rhombus is a 2D shape.
2d
this is the shape of 2d cone
10 sided 2D shape is called a decagon 20 sided 2D shape is called a icosagon 30 sided 2D shape is a swimming pool 40 sided 2D shape is unknown 50 sided 2D shape is unknown 60 sided 2d shape is unknown 70 sided 2d shape is unknown 80 sided 2d shape is unknown 90 sided 2d shape is unknown 100 sided 2d shape is unknown 110 sided 2d shape is unknown 111 sided 2d shape is unknown 120 sided 2d shape is unknown 130 sided 2d shape is unknown
Half a sphere, which is a 3D shape, is called a hemisphere. The semi-circles in the question is a 2D shape and will make a circle.
2d
it a triangle as a 2d shape
The shape of 2D is a flat surface.