Question

Which of the following statements are true ?

(i) All cubes are cuboids.

(ii) All cuboids are cubes.

(iii) A cube has 6 faces, 8 corners, 12 edges.

(iv) A cube has 8 faces, 12 corners and 6 edges.

• A. (i)
• B. (i) and (iii)
• C. (ii) and (iv)
• D. (i) and (iv)

Answer 1

The correct option is B

(i) and (iii)

A cube is a pile of squares whereas a cuboid is a pile of rectangles. A square is a special kind of rectangle, it is one where all the sides have the same length. Thus, every square is a rectangle. Hence, all cubes are cuboids. Therefore (i) is true.

In the figure, the 8 corners are highlighted with yellow circles. The 12 edges are highlighted with orange lines . The 6 faces are highlighted in black . Hence (iii) is true. So, statements (i) and (iii) are true.