Page 2 - Lesson notes- Measuring length of curved line

Activity:
To measure the length of a curved line using a thread and divider, and understand
estimation in measurement.
Materials Required
• Thread or string

• Ruler or meter scale
• Divider
• Curved line drawn on paper (e.g., wave-shaped curve)
• Pencil, eraser
• Worksheet for recording observations
Procedure
Part A: Measuring Curved Line Using Thread
1. Take a piece of string or thread.
2. Place it carefully along the curved
line, adjusting it to fit the bends of the
curve.
3. Mark the point on the thread where
the curved line ends.
4. Straighten the thread and measure it using a ruler.
5. Record the measurement.
Part B: Measuring Curved Line Using a Divider

1. Set the divider tips 1 cm apart using a ruler.
2. Place one tip of the divider at the start of the
curved line.
3. Move the divider along the curve, marking
each segment.
4. Count the number of segments.
5. Measure the leftover part if any using the divider or a ruler.
6. Use the formula:
Length of curve = (number of segments × divider tip distance) + leftover length
Part C: Estimation Activity
1. Estimate the length of your pencil before measuring.
2. Estimate the height of your desk.
3. Measure both using a ruler or measuring tape and compare with your

estimates.
Conclusion
• The thread and divider methods both help in measuring curved lines
accurately.
• Estimation is a useful daily life skill and can be fairly accurate with practice.
• Understanding both exact measurement and estimation improves real-life
problem-solving.