Measurement of Length
The distance of something from one end to the other is called length. It can be measured using a ruler, a measuring tape, a metre rod, and so on, whichever is convenient for the required purpose.
While measuring length using a ruler, we should take the following precautions:
- Care should be taken to keep the ruler along the length of the object.
- If the edge of the ruler is worn out or broken, the measurement should be started from any fully clear. For example, if you measure from 2 cm mark to the 7 cm mark, the length is 5 cm (7 cm – 2 cm = 5 cm).
- Eyes should be exactly above the point where the measurement is to be taken. If your eyes are at different positions, you might get wrong readings.
Using a Divider to Measure Length
A divider is used to measure the distance between two points. Let us see how.
Measuring the Length of a Curved Line
The length of a curved line can be measured using a string. The string is placed along the curved line and its ends are marked on the string.
The length of the string between the marked points is measured with a ruler
Activity
Aim: To find the length of a curved line.
Materials needed: A ruler, a measuring tape, a string, a sketch pen and a leaf.
Method:
- Draw a curved line on a piece of paper.
- Place the string along the curved line. Make sure the string covers every bit of the curved line.
- Mark the points where the curved line begins and ends on the string.
- Now stretch out the string along the length of a ruler (or a stretched out measuring tape, if the curved line is long) and measure the distance between the two marks on the string.
- Try out different curved lines, like the outline of a leaf or even your waist (for this you can use the measuring tape directly).