Question

Which of the following picture is not a 3D figure.
a).

b).

c).

d).

Answer 1

Hint: We would solve the above-given question by first understanding the definition of 3D geometry and then we would analyze the given option to get which figure is not a 3D figure.

Complete step by step answer:
The above question is a simple question of 3-dimensional geometry. At first, we would understand the definition of 3-dimensional geometry. In geometry, a 3-dimensional shape is defined as a solid figure or an object or an object or shape that has three dimensions that is length, breadth, height. Unlike a 2-dimensional figure which has only length and breadth, a 3-dimensional figure thickness or depth. Also, almost all 3-dimensional shapes have more than one face except a sphere which has only one curved face.
Now, we will analyze the option and check whether it is the 3-D figure or not.
a). We can see that it is a sphere and as we have discussed above, a sphere is a 3-D figure with only 1 curved face.
b). We can see that the given figure is a cone that has more than 1 face, that is it has 1 flat face and one curved face. So, it is also a 3D- figure.
c). We can see that the given figure is a cube which has length, breadth, and height. So, it is also a 3D- figure.
d). We can see that the given figure is a square that has only 2-dimensions, that is length and breadth. Hence, it is not a 3D-figure.
So, option (d) is our correct answer.

Note:
 Students are required to note that when a shape or object has depth or thickness or its dimension is extended in three directions then it is always a 3D-figure or object.