## RS Aggarwal Class 6 Math Nineteenth Chapter Three-Dimensional Shapes Exercise 19 Solution

## EXERCISE 19

**SOLID** – *An object that has a shape and size is called a solid.*

**CUBOID **– *Solids such as a wooden box, a match box, a brick, a book, an almirah, etc., are all in the shape of a cuboid.*

**FACES **– *A cuboid has six rectangular faces.*

**EDGES **– *Two adjacent faces of a cuboid meet in a line segment, called an edge of the cuboid. A cuboid has 12 edges.*

**VERTICES **– *Three edge of a cuboid meet at a point, called a vertex. A cuboid has 8 vertex.*

**CUBE **– *A cuboid whose length and height are equal is called a cube. *

**CYLINDER **– *Objects such as a circular pillar, a circular pipe, a test tube, a circular storage tank, a measuring jar, a gas cylinder, a circular powder tin, etc., are in the shape of a cylinder.*

**SPHERE** – *An object which is in the shape of a ball is said to have the shape of a sphere.*

**CONE **– *Objects such as an ice-cream cone, a conical tent, a conical vessel, a clown’s cap, etc., are in the shape of a cone.*

**TRIANGULAR PRISM** – *A solid whose lateral faces are rectangular and the bases are congruent triangles, is called a triangular prism.*

**PYRAMID** – *A solid whose base is a plane rectilinear figure and whose side faces are triangles having a common vertex, called the vertex of the pyramid.*

**SQUARE PYRAMID** – *A solid whose base is a square and whose side faces are triangles having a common vertex is called a square pyramid.*

**TRIANGULAR PYRAMID** – *A solid whose base is a triangle and whose side faces are triangles having a common vertex is called a triangle pyramid.*

Mark (√) against the correct answer in each of Q.1 to Q.6.

**(1) A cuboid has**

Ans: (c) length, breadth and height

**(2) A dice is an example of a **

Ans: (c) cone

**(3) A gas pipe is an example of a **

Ans: (d) cylinder

**(4) A football is an example of a **

Ans: (c) sphere

**(5) A brick is an example of a **

Ans: (b) cuboid

**(6) An ice-cream cone is an example of a **

Ans: (d) none of these

**(7) Fill in blanks:**

(i) An object that occupies space is called a __solid__.

(ii) A cuboid has __6__ faces, __12__ edges and __8__ vertices.

(iii) The __opposite__ faces of a cuboid are identical.

(iv) A __sphere__ has no vertex and no edge.

(v) All the faces of a __cube__ are identical.

(vi) A square pyramid has __4__ lateral triangular faces and __8__ edges.

(vii) A triangular pyramid has __3__ triangular lateral faces and __6__ edges.

(viii) A triangular prism has __6__ vertices, __3__ rectangular lateral faces, __2__ triangular bases and __9__ edges.

**(8) Give examples of four objects which are in the shape of:**

(a) A cone = Ice-cream cone, clown’s cap, conical tent, conical vessel

(b) A cuboid = A brick, a book, a chalk box, a match box.

(c) A cylinder = Circular pillar, circular pipe, measuring jar, test tube