Measuring Line Segments

Measuring Line Segments:

• A line segment corresponds to the shortest distance between two points. A line segment is a fixed portion of a line.

• The distance between the endpoints of a line segment is its length.

• Line segments can be measured by
  i) Comparison by observation:
  We can tell which line segment is greater than other just by observing the two line segments but it is not sure.
  
  
  
  ii) Comparison by tracing:
  This method depends upon the accuracy in tracing the line segment.

  In this method we have to trace one line on paper then put the traced line segment on the other line to check which one is greater.

  But this is a difficult method because every time to measure the different size of line segments we have to make a separate line segment.

  
  
  
  iii) Comparison using ruler and divider:
  We can use a ruler to measure the length of a line segment. Put the zero mark at point A and then move toward l to measure the length of the line segment, but it may have some errors on the basis of the thickness of the ruler.
  
  

• A graduated ruler and the divider are useful to compare lengths of line segments.

1. Open the divider.
2. Place the endpoint of one of its arms at A and the endpoint of the second arm at B.
3. Taking care that the opening of the divider is not disturbed, lift the divider and place it on the ruler. Ensure that one endpoint is at the zero mark of the ruler.
4. Now read the mark against the other endpoint.

• Positioning error: To get the correct measure, the eye should be correctly positioned, just vertically above the mark. Otherwise, errors can happen due to angular viewing.