**Exercise 19**

**Mark against the correct answer in each of Question 1 to Question 6.**

**Question 1:**

**A cuboid has**

**(a) length only**

**(b) length and breadth only**

**(c) length, breadth and height**

**(d) thickness only**

**Solution:**

(c) length, breadth and height

A cuboid is a 3-dimensional figure.

**Question 2:**

**A dice is an example of a **

**(a) cuboid**

**(b) cube**

**(c) cone**

**(d) cylinder**

**Solution:**

(b) cube

**Question 3:**

**A gas pipe is an example of a **

**(a) cuboid**

**(b) cube**

**(c) cone**

**(d) cylinder**

**Solution:**

(d) cylinder

**Question 4:**

**A football is an example of a **

**(a) cylinder**

**(b) cone**

**(c) sphere**

**(d) none of these**

**Solution:**

(c) sphere

**Question 5:**

**A brick is an example of a **

**(a) cube**

**(b) cuboid**

**(c) prism**

**(d) cylinder**

**Solution:**

(b) cuboid

**Question 6:**

**An ice-cream cone is an example of a **

**(a) cuboid**

**(b) cube**

**(c) pyramid**

**(d) none of these**

**Solution:**

(d) None of these

It’s a cone.

**Question 7:**

**Fill in the blanks:**

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

**(ii) A cuboid has ______ faces, ______ edges and ________ vertices.**

**(iii) The ______ faces of a cuboid are identical.**

**(iv) A ________ has no vertex and no edge.**

**(v) All the face of a ________ are identical.**

**(vi) A square pyramid has ________ lateral triangular faces and _______ edges.**

**(vii) A triangular pyramid has _________ triangular lateral faces and ________ edges.**

**(viii) A triangular prism has ________ vertices, ________ rectangular lateral faces, __________ triangular bases and ________ edges.**

**Solution:**

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

(ii) A cuboid has 6 rectangular 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 face 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.

**Question 8:**

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

**(a) a cone**

**(b) a cuboid**

**(c) a cylinder**

**Solution:**

(a) An ice cream cone, a conical tent, a clown’s cap and a conical vessel are in the shape of a cone.

(b) A wooden box, a match box, a brick and an almirah are in the shape of a cuboid.

(c) A measuring jar, a gas cylinder, a test tube and a circular pillar are in the shape of a cylinder.