Chapter 16: Understanding Three Dimensional Shapes Exercise 16.2
Question: 1
Give two new examples of each of the for three-dimensional shapes:
(i) Cone
(ii) Sphere
(iii) Cylinder
(iv) Cuboid
(v) Pyramid
Solution:
(i) A school bell and a funnel.
(ii) A tennis ball and a model of a globe.
(iii) Drink cans and delivering pipes for a water and gas.
(iv) A match box and brick.
(v) A paper- weight and a tower like the Eiffel tower.
Question: 2
What is the shape of:
(i) instrument box
(ii) a brick
(iii) a match box
(iv) a rod- roller
(v) a sweet laddoo
Solution:
(i) My instrument box is in the shape of a cuboid.
(ii) A brick is in the shape of the cuboid.
(iii) A match – box is in the shape of a cuboid.
(iv) A road – roller is in the shape of a cylinder.
(v) A sweet laddoo is shaped like a sphere.
Objective Type Questions:
Question: 1
Total number of faces of a cuboid is
(a) 4
(b) 6
(c) 8
(d) 12
Solution:
(b) 6
Question: 2
Total number of edges of a cuboid is
(a) 4
(b) 6
(c) 8
(d) 12
Solution:
(d) 6
Question: 3
Number of faces of a cuboid is
(a) 4
(b) 6
(c) 8
(d) 12
Solution:
(c) 8
Question: 4
Which one of them is example of cuboid?
(a) a dice
(b) a football
(c) a gas pipe
(d) an ice- cream cone
Solution:
(a) A dice
Question: 5
A brick is an example of
(a) cube
(b) cuboid
(c) prism
(d) cylinder
Solution:
(b) Cuboid
Question: 6
A gas pipe is an example of
(a) cone
(b) a cylinder
(c) cube
(d) sphere
Solution:
(b) A cylinder
Question: 7
If the base radius and height of a right circular cone are 3 cm and 4 cm in lengths, then the slant height is
(a) 5 cm
(b) 2 cm
(c) 25 cm
(d) 6 cm
Solution:
(a) 5 cm
Question: 8
The number of faces of a triangular pyramid is
(a) 3
(b) 4
(c) 6
(d) 8
Solution:
(b) 4
A pyramid is called a triangular pyramid if its base is a triangle.
Question: 9
The number of edges of a triangular pyramid is
(a) 3
(b) 4
(c) 6
(d) 8
Solution:
(c) 6
Question: 10
A tetrahedron is a pyramid whose base is a
(a) triangle
(b) square
(c) rectangle
(d) quadrilateral
Solution:
(a) Triangle