NCERT Solutions for Class 6 Maths Chapter 4 Exercise 4.4

Class VI Mathematics textbook Ex. 4.4 of chapter 4 Basic Geometrical Ideas in PDF file format free updated for CBSE new session. The digital contents for class 6 Maths is available in Hindi Medium and English Medium format. Videos related to exercise 4.4 class 6 Maths are also given below to use free.

A line segment can be measured by using various geometrical instruments such as ruler, divider etc. Let us have a brief idea about these instruments.

A ruler is smaller than a metre scale. Usually the length of a ruler is 6 inches (15 cm approximately) or 1 foot (30 cm approximately). A ruler is a straight edged thin strip of plastic or steel or some other metals. It has centimetre and millimetre marks on one edge. The opposite edge has inch marks and tenth of inch mark. The marks on the ruler is called graduations and the ruler is called a graduated ruler.
1 inch = 2.54 cm.

A pair of dividers has two arms, which are hinged together. Each has a sharp metal end point. The distance between metallic end point may be increased or decreased as per requirement.

The instrument compasses have two arms, which are hinged together. One of the arms has a metal end point. The other arm has screw arrangement which can tightly hold a pencil. The end point of the pencil can be adjusted at any distance from the metallic end point.

In order to measure the length of a given line segment MN, we place the ruler with its edge along the segment MN such that zero (0) mark of the ruler coincides with the point M. Now we read the mark on the ruler which is against the point N. The reading on the ruler corresponding to the end point N is the length of the line segment MN.

We have learnt about the measurement of the lengths of line segments by using a ruler. Generally, the marks on the ruler are not at the same level as the segment MN because of the thickness of the ruler. This may cause some error in placing zero mark against one end of the line segment or reading the mark against the other end of the line segment. To avoid this difficulty, we can measure line segments with the help of a divider as follows:

Let MN be the line segment. We open the divider such that the end point of one of its arms is at M and end point of the second arm is at N. Then we lift the divider and without disturbing its opening, place it on the ruler so that the end point of one arm is at zero (0) mark. We then read the mark against the end point of the second arm of the divider.