Page 280 - Start Up Mathematics_7

4. Match the figures with their corresponding views.

Object View

(a) Top view of a jar (i)

(b) Top view of a bottle (ii)

(c) Top view of a car (iii)

2 kg kg
(d) Front view of a weight 2 (iv)

(e) Side view of a cylinder (v)

Group Activity

Objective: To form a three-layered structure using cubes as shown in the given figure
Material required: Cubes of identical size, pen, paper

Answer the following:
(a) How many cubes are there in the 3 layers?
(b) How many cubes are used for the middle layer?

(c) How many cubes are required for the base layer? If this
pattern is continued, how many cubes would be in the
base layer of a structure having 4 layers, 5 layers, n layers?
Note: Make identical cubes of cardboard if readymade cubes are not available.

Thinking Skills

1. What is the relation between the faces, edges and vertices of a polyhedron? An icosahedron
has 12 vertices, 20 faces and n edges. Find n.

272