Mathematics
Why is it better to use a divider and a ruler than a ruler only, while measuring the length of a line segment?
Answer
When we measure the length of a line segment using a ruler only, the following errors may occur:
(i) The thickness of the ruler may cause an error in measurement.
(ii) The angular positioning of the eye may cause an error in measurement (parallax error).
A divider is a pair of pointers having sharp ends. When we use a divider along with a ruler, the sharp ends of the divider give the exact position of the endpoints of the line segment on the ruler.
Hence, it gives accurate measurement and avoids errors due to the thickness of the ruler or the positioning of the eye (due to angular viewing).
Related Questions
In the adjoining figure, compare the line segments with the help of a divider and fill in the blanks by using the symbol >, = or <:
(i) AB …. CD
(ii) BC …. AB
(iii) AC …. BD
(iv) CD …. BD
If A, B and C are collinear points such that AB = 6 cm, BC = 4 cm and AC = 10 cm, which one of them lies between the other two?
In the adjoining figure, verify the following by measurement:
(i) AB + BC = AC
(ii) AC - BC = AB
In the adjoining figure, verify by measurement that:
(i) AC + BD = AD + BC
(ii) AB + CD = AD - BC