which three points must be kept in mind while measuring the length of an object with the help of a ruler?
1. Place the ruler along the line you wish to measure as close to it as possible.
2. Your eye must be exactly above the point at which your making your measurement.Its better one keep one eye closed while making the measurement.
3.Try and make three measurements and take their average to get an accurate measurement..
4. Preferably a non metallic ruler(like plastic or glass) is to be used in extreme temperatures,to avoid errors arising from thermal expansion and contraction of the metallic ruler .
2. Your eye must be exactly above the point at which your making your measurement.Its better one keep one eye closed while making the measurement.
3.Try and make three measurements and take their average to get an accurate measurement..
4. Preferably a non metallic ruler(like plastic or glass) is to be used in extreme temperatures,to avoid errors arising from thermal expansion and contraction of the metallic ruler .