We will discuss here about constructing a line segment. We know how to draw a line segment of a certain length. Suppose we want to draw a line segment of 4.5 cm length.
We follow the following steps as given below:
Step I: We place a scale on a paper sheet as shown below.
Step II: We place the sharp point of a pencil on the point which coincides with 0 on the scale and name it as A.
Step III: We mark another point B which coincides with the fifth millimetre division after the 4th centimetre. (1 small division = 1 mm.)
Step IV: We join both points A and B by drawing a line segment with a fine pointed pencil. The line segment AB is of 4.5 cm length.
Drawing a Line Segment:
Now, let us learn how to draw a line segment of a given length.
Step I: Place the ruler on the paper. Then mark two points P and Q against the marks 0 and 9 of the scale.
Step II: Keeping the scale evenly, move the pencil from P to Q along the edge of the scale. The line segment PQ is of length 9 cm.
Suppose you have to draw a line segment AB of length 7.7 cm.
Place the ruler on the paper.
Mark a point against the ‘0’ mark and another point against 7.7 cm mark.
Join the points by pressing the scale evenly and moving the tip of the sharp pencil along the edge of the scale.
Remove the scale and name the points as A and B.
The line segment drawn is of 7.7 cm.
Questions and Answers on Constructing a Line Segment
I. Draw line segments of the following lengths using the ruler:
(i) 9 cm
(ii) 3 cm
(iii) 10 cm
(iv) 5 cm
(v) 7 cm
II. Draw two lines segments PQ and QR of length 4 cm each such that they meet at point Q. Measure the length of line segment PR.