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4. Look at the picture and answer the
following questions.

(a) The sunlight is an example of which one:
a ray, a line or a line segment?

(b) Count the number of line segments in the
boat.

(c) At how many points do vertical and horizontal line segments meet?

Be Aware
Logical Thinking • We need at least two points to
Think Tank
draw a line segment.
Horizon is the place where the earth and sky appear • A point and a line have no
to meet. Is the horizon an example of a line? thickness.

measurinG and drawinG a line seGment

measuring a line segment

A line segment has a definite length, so it can be measured and drawn 0 cm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
on paper.
0 1 2 3 4 5 6
A ruler is used to measure the length of different line segments. Each ‘cm’ is divided into
10 equal parts, called mm (millimetre).

To measure the length of a line segment, we follow the steps as given below:

1. Place a ruler along the line segment, say PQ.

2. Align the starting point of the line segment with the zero mark of the ruler. Remember

to adjust ‘0’ on the ruler at point P. P Q

3. Read the mark on the ruler against the 0 cm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
other point Q on the ruler. It ends at 0 1 2 3 4 5 6

the 5 cm mark of the ruler.
So, the length of the given line segment PQ is 5 cm.

drawing a line segment

To draw a line segment of a given length, say 3 cm, we follow these steps.

Step 1: Place the ruler on a plane paper and hold it with one hand.

0 cm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0 1 2 3 4 5 6

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