Question

Which of the following have 6 flat surfaces and no curved surface?
(a) Prism
(b) Pyramid
(c) Cube
(d) Cuboid

Answer 1

Hint: First draw the figure of all the shapes given in the options. Now, check the total number of flat and curved surfaces present in each of them to select the correct option(s). If any surface is rolled then it is called the curved surface otherwise it is a flat one.

Complete step by step solution:
Here we have been provided with four different shapes in four options and we are asked to select the correct option in which the mentioned figure has 6 flat surfaces and 0 curved surfaces. First let us know about flat and curved surfaces.
If we fold a flat surface then it forms a curved surface. For example, we can fold a rectangle which has a flat surface to form a cylinder which has a curved surface. However, the two circular parts are still flat in nature. Similarly, we can form a cone using a semi – circle (flat in nature). The cone has a flat surface in the form of a base circle and a curved surface.
Let us come to the question. We have to draw four shapes given in the options.
(a) Prism

Clearly we can see that here we have 5 flat surfaces and 0 curved surfaces. So it is not our answer.
(b) Pyramid

Clearly we can see that here also we have 5 flat surfaces and 0 curved surfaces. So it is also not our answer.
(c) Cube

Clearly the cube has 6 flat surfaces and no curved surface. So it can be our answer.
(d) Cuboid

Clearly the cuboid also has 6 flat surfaces and no curved surface. So it can also be our answer.
Hence option (c) and (d) both are correct answers.

Note: Note that there are many types of prisms and pyramids but hare we have taken the triangular prism and triangular pyramid because nothing is mentioned so we have to consider them only. Remember that circle, triangle, square, rectangle, rhombus, parallelogram are all flat. If they will be folded then they will form a curved surface.