It is a 3-D shape because a tetrahedron can be folded into a net!
2D - the triangle 3D - the tetrahedron (i.e. it has a triangle on each side and there are 4 sides.
tetrahedron is a 4 faced 3d shape.
A camera is a 3D shape. A photograph is a 2D projection of a 3D shape onto a 2D shape.
A 'Quadrilateral' is a 2-dimensional, 4 sided polygon. The following names are quadriltaerals;- square, rectangle, rhombus, trapezium, parallelogram, kite, and an irrelgular qudarilateral. NB In 3-dimensional space, ther equivlanet is a 'CUBOID'.
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.
It's a 2D shape.
A piece of paper is 3D.
2d
2D.
a pyramid is a 3D shape :)
Well, a tetrahedron has four sides. A regular tetrahedron is a triangular pyramid.
It's a 2D shape.