Page 120 - ICSE Math 4

Exercise 9.5

1. Construct a circle of (a) radius 4 cm and (b) diameter 10 cm.

2. Name the following parts from the given fi gure of a circle. B
(a) Centre (b) Radius (c) Diameter P
A
3. Find the diameters of a circle for the given radii.

(a) 12 cm (b) 8 cm (c) 10 cm

4. Find the radii of a circle for the given diameters.

(a) 18 cm (b) 14 cm (c) 4 cm

Nets

A shape that has only two dimensions, i.e., length and breadth, is called a two-dimensional
(2D) shape.

A shape that has three dimensions, i.e., length, breadth and height, is called a solid or a
three-dimensional (3D) shape.

Now let’s learn how to create a 3D shape from a 2D shape using a net.
A net is a two-dimensional shape that can be folded to Back
create a three-dimensional object. We can tell what

3D fi gure a net will create when folded by looking at om Top
its parts. Top Le Bo Right Front Right
Look at the given net. The plane fi gures on its parts are
rectangles. Thus, it can be folded to create a cuboid.
Front
The nets of some more three-dimensional fi gures given in the table shown below.

3D Figure or
Shape

Net(s)

View

View of an object means how it looks when it is seen from diff erent posi ons. There are

basically three views. They are top view, front view and side view.

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